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  • 1.
    Abdollahi, Morteza
    et al.
    Faculty of Engineering, Urmia University, Iran.
    Bahrami, Ataallah
    Department of Mining Engineering, Faculty of Engineering – Urmia University, P.O. Box 57561/51818, Iran.
    Saleh Mirmohammadi, Mir
    School of Mining Engineering, University of Tehran, Iran.
    Kazemi, Fatemeh
    Faculty of Engineering – University of Kashan, Iran.
    Danesh, Abolfazl
    Complex of Copper Processing – Sungun, Headquarters Rd, Tabriz, East Azerbaijan Province, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    A process mineralogy approach to optimize molybdenite flotation in copper: molybdenum processing plants2020In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 157, article id 106557Article in journal (Refereed)
    Abstract [en]

    The Sungun copper-molybdenum operation in Iran uses a typical copper-molybdenum flowsheet to produce separate copper and molybdenum concentrates through flotation and regrinding of the rougher concentrates arising from the primary circuit. This site was used as a case study limited to the feed and products of the copper-molybdenum separation circuit, in which process mineralogy might improve the quality of the molybdenum concentrate thorough diagnostic analysis of key flowsheet streams. The undesirable presence of copper in the molybdenum concentrate was identified as a key focus for the investigation by process mineralogy, which has a history of successful process diagnosis. This is because it develops information on minerals, which is far more informative than chemical assays alone. Together with the assays, the mineralogical data inform the investigator of the type and quantity of minerals present, their state of liberation and textural associations, and metal recovery.

    A key finding was that the appearance of chalcopyrite in the molybdenum concentrate was due to the presence of a chalcopyrite-pyrite texture that avoided the chalcopyrite depression in the molybdenum circuit because of suitable pyrite flotation conditions. Recovery of liberated pyrite to this concentrate also diluted the molybdenum concentrate. The open-circuit format of the regrind circuit also contributed to the unnecessary production of ultrafine particles. This flaw expressed itself as ultrafine losses of molybdenite to the flotation tailings.

  • 2.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Faculty of Engineering, Urmia University, Urmia, Iran.
    Danesh, Abolfazl
    Complex of Copper Processing – Sungun, East Azerbaijan Province, Headquarters Rd, Tabriz, Iran.
    Kazemi, Fatemeh
    Faculty of Engineering, University of Kashan, Kashan, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Abdollahi, Morteza
    Faculty of Mining Engineering, Isfahan University of Technology, Isfahan, Iran.
    The Evaluation of Starch-Based Flocculant on the Thickener Operation in the Molybdenum Processing Plant and Competency of Molybdenite Flotation2022In: Mining, Metallurgy & Exploration, ISSN 2524-3462, Vol. 39, no 3, p. 1255-1266Article in journal (Refereed)
    Abstract [en]

    The type and dosage of flocculants used in the middle thickener of the copper-molybdenum plant, in addition to adjusting the quality of recycled process water, is very effective on the floatability of molybdenite. In this study, the effect of starch-based flocculant (wheat starch) was investigated on the efficiency of middle thickener and molybdenite flotation, in the molybdenum processing plant. First, sampling from overflow and underflow of the middle thickener in Mo processing circuit (in industrial scale), in the presence and absence of starch, were collected. The polished sections of samples from the overflow and underflow of the thickener were studied in order to determine the effect of starch on particles settling with different shapes. Microscopic studies show that molybdenite plate-like coarse particles are transferred to the thickener overflow (process water) in the presence of starch flocculant, whereas molybdenite fine particles present in the underflow are often needle-shaped. In addition, in terms of grade distribution, the grade of molybdenum in the thickener overflow is higher than that of copper and iron. Then, after sedimentation tests (in laboratory scale) with different concentrations of flocculant, flotation tests were performed on test samples. According to the results from laboratory studies, increasing the dosage of starch from 0 to 1000 g/t increased the recovery of molybdenite flotation and reduced the access of copper minerals to molybdenite concentrate. In this case, molybdenum recovery (in lab tests) is increased by about 5% compared to the case of not using starch. While the increase in the recovery of molybdenum by adding starch to the middle thickener in the industrial scale is about 10%. In higher dosages of starch (2000 g/t), the trend is reversed (in the lab and industrial scale) and molybdenum recovery decreased sharply due to the decrease in contact angle and depression, whereas the amount of copper transferred to the molybdenum concentrate increased.

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  • 3.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Urmia University, Urmia, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Hosseini, Mohammad Raouf
    Department of Mining Engineering, Isfahan University of Technology, Isfahan, Iran.
    Kazemi, Fatemeh
    Department of Mining Engineering, Urmia University, Urmia, Iran.
    Abdollahi, Morteza
    Department of Mining Engineering, Urmia University, Urmia, Iran.
    Danesh, Abolfazl
    Mineral Processing Plant, Sungun Mine, Tabriz, Iran.
    Combined Effect of Operating Parameters on Separation Efficiency and Kinetics of Copper Flotation2019In: Mining, metallurgy & exploration, ISSN 2524-3462, Vol. 36, no 2, p. 409-421Article in journal (Refereed)
    Abstract [en]

    This study aims to investigate the effects of operational variables on concentrate grade, recovery, separation efficiency, and kinetic parameters of the copper flotation process. For this purpose, the effects of the pulp solids content, collector and frother dosage, and preparation and concentrate collection time were studied using a Taguchi experimental design. The results of statistical analyses indicated that the concentrate collection time and pulp density were the most influential parameters on concentrate grade. Considering copper recovery, concentrate collection time, collector dosage, and pulp density were the most significant variables, in decreasing order of importance. Also, the separation efficiency was mostly influenced by the concentrate collection time. Furthermore, kinetic studies showed that the second-order rectangular distribution model perfectly matched the experimental flotation data. The highest kinetic constant of 0.0756 s−1 was obtained from the test, which was performed with 35% solids content and 40 and 20 g/t collector and frother, respectively. The highest predicted copper recovery of 99.57% was obtained from the test at 30% solids content, and the collector and frother dosages of 40 and 15 g/t, respectively.

  • 4.
    Bahrami, Ataallah
    et al.
    Department of Mining EngineeringUrmia UniversityUrmiaIran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Mirmohammadi, Mirsaleh
    School of Mining EngineeringUniversity of TehranTehranIran.
    Sheykhi, Behnam
    Department of Mining EngineeringUrmia UniversityUrmiaIran.
    Kazemi, Fatemeh
    Department of Mining EngineeringUrmia UniversityUrmiaIran.
    The beneficiation of tailing of coal preparation plant by heavy-medium cyclone2018In: International journal of coal science & technology, ISSN 2095-8293, Vol. 5, no 3, p. 374-384Article in journal (Refereed)
    Abstract [en]

    Dense-medium cyclones have been used for beneficiation of fine particles of coal. In this study, the usability of cyclones in the beneficiation of tailings of a coal preparation plant was investigated. For this purpose, separation tests were conducted using spiral concentrator and heavy medium cyclones with the specific weight of medium 1.3–1.8 (g/cm3) on different grading fractions of tailing in an industrial scale (the weight of tail sample was five tons). Spiral concentrator was utilized to beneficiate particles smaller than 1 mm. In order to evaluate the efficiency of cyclones, sink and float experiments using a specific weight of 1.3, 1.5, 1.7 and 1.9 g/cm3, were conducted on a pilot scale. Based on the obtained results, the recovery of floated materials in cyclones with the specific weight of 1.40, 1.47 and 1.55 g/cm3 are 17.75%, 33.80%, and 50%, respectively. Also, the cut point (ρ50), which is the relative density at which particles report equally to the both products are 1.40, 1.67 and 1.86 g/cm3. The probable errors of separation for defined specific weights for cyclones are 0.080, 0.085 and 0.030, respectively. Also, the coefficients of variation was calculated to be 0.20, 0.12 and 0.03. Finally, it could be said that the performance of a cyclone with a heavy medium of 1.40 g/cm3 specific weight is desirable compared with other specific weights.

  • 5.
    Bahrami, Ataallah
    et al.
    Urmia University, Iran .
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Sharif, Jafar Abdollahi
    Urmia University, Iran .
    Kazemi, Fatemeh
    Urmia University, Iran .
    Abdollahi, Morteza
    Urmia University, Iran .
    Salahshur, Abbas
    Urmia University, Iran .
    Danesh, Abolfazl
    Urmia University, Iran .
    A geometallurgical study of flotation performance in supergene and hypogene zones of Sungun copper deposit2021In: Mineral Processing and Extractive Metallurgy: Transactions of the Institute of Mining and Metallurgy, ISSN 2572-6641, E-ISSN 2572-665X, Vol. 130, no 2, p. 126-135Article in journal (Refereed)
    Abstract [en]

    The feed of mineral processing plants, usually consist of different minerals from various geological zones, which show different behavior in separation processes. In this research, samples from supergene and hypogene zones were provided to investigate the flotation behavior of copper minerals. Flotation experiments were carried out in three phases of supergene sample, hypogene sample and mixed samples. Based on the results, the recovery rate of the mixed sample was 83.61%, which is 7.63% and 1.79% higher than the recovery of the samples of hypogene and supergene zones, respectively. The concentrate grade values obtained for blended, hypogene zone and supergene zone are 10.32%, 2.81% and 12.37%, respectively. The maximum values of flotation constant and infinite recovery are 0.956 (s−1) and 88.833% for the mixed sample. It was also concluded that the highest amount of k and infinitive recovery were related to supergene zone sulfide flotation which are 0.831 (s−1) and 84.33% respectively.

  • 6.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Faculty of Engineering, Urmia University, Urmia, Iran.
    Hassanpour Kashani, Reza
    Department of Mining Engineering, Faculty of Engineering, Urmia University, Urmia, Iran.
    Kazemi, Fatemeh
    Faculty of Engineering, University of Kashan, Kashan, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Oxidation-reduction effects in the flotation of copper sulfide minerals and molybdenite – A proof of concept at industrial scale2022In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 180, article id 107505Article in journal (Refereed)
    Abstract [en]

    Redox potential (Eh) control plays a significant role during sulfide mineral flotation by influencing the reactions on the surface of the minerals and accordingly the flotation behaviour. In this study, the metallurgical performance of typical copper sulfide minerals, molybdenite as well as gangue minerals (e.g., pyrite, tennantite, and enargite) under different pH and Eh conditions of the flotation cell were investigated. The copper and molybdenum processing plant at the Sungun complex-Iran were selected as a case study. For this purpose, Eh of flotation cells of phases 1 and 2 of copper and molybdenum processing circuits – Sungun complex – were measured by off-line method. After performing chemical analysis, the mineralogical study of the input load and products of each of the aforementioned flotation circuits in the rougher, cleaner, re-cleaner, and scavenger stages was performed. Based on the results, the potential in cells of phases 1 and 2 of copper concentration plants is in the range of −60 to −100 mV; and for the molybdenum plant, is in the range of −500 to −700 mV. The potentials of more than −100 mV in the phases of copper concentration plants have created suitable conditions for the separation of copper sulfide and molybdenite minerals from gangue minerals, especially pyrite. Adjustment of Eh in the range of −500 to −700 mV in the molybdenum processing plant has also led to the depression of copper minerals and the flotation of molybdenite, resulting in the effective separation of these minerals. However, grade analysis and mineralogical studies indicate the misplaced copper minerals into tailings, the passage of chalcopyrite and pyrite to molybdenum concentrate, the misplaced molybdenite to copper concentrate, and also the presence of minerals containing harmful elements such as arsenic in copper concentrate. Eh fluctuations in phase 1 and 2 of copper plants, the interaction of copper sulfide minerals, especially chalcopyrite with pyrite (and the depression of pyrite in Eh more than −100 mV), are reasons for the misplaced copper minerals into tailings. The interaction of chalcopyrite and pyrite with molybdenite and the high flotation tendency of molybdenite at the potential of +600 mV is the main factor in increasing the Cu and Fe grade in molybdenite concentrate. The interaction of copper minerals with arsenic-bearing minerals and the similar flotation behavior of these minerals in the potential of the rougher cells of the molybdenum processing plant has increased the arsenic grade in the copper concentrate or molybdenum tailings.

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  • 7.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Faculty of Engineering – Urmia University, Urmia, Iran.
    Kazemi, Fatemeh
    Mineral Processing, Faculty of Engineering – University of Kashan, Kashan, Iran.
    Abdollahi, Morteza
    Mineral Processing, Faculty of Mining Engineering – Isfahan University of Technology, Isfahan, Iran.
    Mirmohammadi, MirSaleh
    School of Mining Engineering, University of Tehran, Tehran, Tehran, Iran.
    Danesh, Abolfazl
    PhD student of Mineral processing, Faculty of Mining Engineering, Sahand University of Technology, Tabriz, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    The effect of grinding circuit efficiency on the grade and recovery of copper and molybdenum concentrates2022In: Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, ISSN 1556-7036, E-ISSN 1556-7230, Vol. 44, no 3, p. 8121-8134Article in journal (Refereed)
    Abstract [en]

    The efficiency of grinding and flotation process in copper-molybdenum processing circuit, largely affected by performance of thickeners and hydrocyclones devices. The goal of this paper is to investigate the effect of the rate-limiting factors on the performance of these devices and consequently on grinding and separation efficiency of the molybdenum processing circuit. So, a full process mineralogical study have been carried out on outputs of thickeners and hydrocyclone of the molybdenite flotation circuit. According to the results, coarse-grained fractions (>50 μm) of the planar molybdenite will not necessarily be recovered by thickener and hydrocyclones. This is especially true for hydrocyclones when the inlet-load rate is high, i.e., the erroneous discharge of planar molybdenite particles from the overflow of hydrocyclone, as well as their floatability in the thickener overflow, can be attributed to the effect of particle shape and size. This issue harms the grade and recovery of flotation due to the increase in the amount of circulating load (regrinding) and consequently the generation of fine particles (<10 μm) in the hydrocyclone-milling circuit. On the other hand, the almost spherical particles of copper minerals, as well as the nonplanar molybdenite fine-grained particles, are easily removed from the hydrocyclone underflow or settled in thickeners. The introduction of copper mineral particles into molybdenum concentrate and vice versa has reduced the quality of the produced concentrate and undesirable flotation performance.

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  • 8.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Faculty of Engineering, Urmia University.
    Kazemi, Fatemeh
    Faculty of Engineering, University of Kashan.
    Alighardashi, Abolghasem
    Department of Civil Engineering, Faculty of Engineering, Shahid Beheshti University.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Abdollahi, Morteza
    Department of Mining Engineering, Faculty of Engineering, Urmia University.
    Parvizian, Armin
    Department of Civil Engineering, Faculty of Engineering, Shahid Beheshti University.
    Isolation and removal of cyanide from tailing dams in gold processing plant using natural bitumen2020In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 262, article id 110286Article in journal (Refereed)
    Abstract [en]

    Gilsonite as a natural occurrence of bitumen and due to the presence of carbon in its structure is a suitable adsorbent for a wide variety of pollutants. In this research, the adsorption of cyanide from the wastewater of gold processing plants using gilsonite were investigated. In this way, the effect of particle size of gilsonite, the weight and mixing time with solution, on the amount of cyanide adsorption have been studied. In addition, in one experiment, the effect of processed gilsonite on its adsorption ability was investigated. Based on the obtained results, the maximum adsorption of 61.64% was obtained in the size range of −1+0.5 and −2+1 mm of gilsonite. With increasing adsorbent weight and mixing time, the cyanide adsorption rate were increased. On the other hand, with the processing of the gilsonite sample, the amounts of adsorption were increased considerably. This study indicated that gilsonite can be used as an isolation and absorbent in the structure and floor of the tailing dumps of mineral processing plants.

  • 9.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Faculty of Engineering, Urmia University, Urmia, Iran.
    Kazemi, Fatemeh
    PhD Student of mineral processing, Faculty of Engineering, University of Kashan, Kashan, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Effect of different reagent regime on the kinetic model and recovery in gilsonite flotation2019In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 8, no 5, p. 4498-4509Article in journal (Refereed)
    Abstract [en]

    Gilsonite is a natural fossil resource, similar to an oil asphalt high in asphaltenes. To determine the effect of reagent regime on the kinetic order and rate of flotation for a gilsonite sample, experiments were carried out in both rougher and cleaner flotation process. Experiments were conducted using different combinations of reagent: Oil-MIBC; gasoline-pine oil; and one test without any collector and frother. According to results, kinetic in the test performed using the oil-MIBC and without any collector and frother were found to be first-order unlike the kinetic in the test conducted using the gasoline-pine oil. Five kinetic models were applied to the modeling of data from the flotation tests by using MATrix LABoratory software. The results show that all experiments are highly in compliance with all models. The kinetic constants (k) in rougher stage were calculated as 0.1548 (s-1), 0.2300 (s-1) and 0.2163 (s-1) for oil-MIBC, gasoline-pine oil, and test without any collector and frother, respectively. These amounts in the cleaner stage were 0.0450 (s-1), 0.1589 (s-1) and 0.0284 (s-1), respectively. The relationship between k, maximum combustible recovery (R) and particle size was also studied. The results showed that the R and k were obtained with a coarse particle size of (-250 + 106) μm in the rougher and (-850 + 500) μm in cleaner flotation processes.

  • 10.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Urmia University, Urmia, Iran.
    Kazemi, Fatemeh
    University of Kashan, Kashan, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Sharif, Jafar Abdolahi
    Department of Mining Engineering, Urmia University, Urmia, Iran.
    The Order of Kinetic Models, Rate Constant Distribution, and Maximum Combustible Recovery in Gilsonite Flotation2019In: Mining, Metallurgy & Exploration, ISSN 2524-3462, Vol. 36, p. 1101-1114Article in journal (Refereed)
    Abstract [en]

    Kinetic models are the most important tool for predicting and evaluating the performance of flotation circuits. Gilsonite is a natural fossil resource similar to an oil asphalt, high in asphaltenes. Here, in order to determine the kinetic order and flotation rate of a gilsonite sample, flotation experiments were carried out in both rougher and cleaner stages. Experiments were conducted using the combinations of oil–MIBC and gas oil–pine oil, with one test without collector and frother. Five kinetic models were applied to the data obtained from the flotation tests using MATLAB software. Statistical analysis showed that the results of the experiment with oil–MIBC were highly in compliance with all models. Kinetic constants (k) were calculated as 0.1548 (s−1) and 0.0450 (s−1) for rougher and cleaner stages, respectively. Rougher and cleaner tests without collector and frother also matched all models well (R2 > 0.98), with kvalues of 0.2163 (s−1) and 0.284 (s−1), respectively. The relationship between flotation rate constant, maximum combustible recovery, and particle size showed that the maximum flotation combustible recovery and flotation rate were obtained in the size range of −250 + 106 μm in the rougher and cleaner stages. The combustible recovery and flotation rate were higher in the rougher flotation process than in the cleaner stage.

  • 11.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Faculty of Engineering, Urmia University, P.O. Box 57561/51818, Urmia, Iran.
    Kazemi, Fatemeh
    Faculty of Engineering, University of Kashan, Kashan, Iran.
    Mirmohammadi, Mirsaleh
    School of Mining Engineering, University of Tehran, Tehran, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Farajzadeh, Saghar
    Department of Mining Engineering, Faculty of Engineering, Urmia University, P.O. Box 57561/51818, Urmia, Iran.
    Configuration of flowsheet and reagent dosage for gilsonite flotation towards the ultra-low-ash concentrate2021In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, article id 15469Article in journal (Refereed)
    Abstract [en]

    Gilsonite has a wide variety of applications in the industry, including the manufacture of electrodes, paints and resins, as well as the production of asphalt and roof-waterproofing material. Gilsonite ash is a determining parameter for its application in some industries (e.g., gilsonite with ash content < 5% used as an additive in drilling fluids, resins). Due to the shortage of high grade (low ash) gilsonite reserves, the aim of this study is to develop a processing flowsheet for the production of ultra-low-ash gilsonite (< 5%), based on process mineralogy studies and processing tests. For this purpose, mineralogical studies and flotation tests have been performed on a sample of gilsonite with an average ash content of 15%. According to mineralogical studies, carbonates and clay minerals are the main associated impurities (more than 90 vol.%). Furthermore, sulfur was observed in two forms of mineral (pyrite and marcasite) and organic in the structure of gilsonite. Most of these impurities are interlocked with gilsonite in size fractions smaller than 105 µm. The size fraction of + 105 − 420 µm has a higher pure gilsonite (approximately 90%) than other size fractions. By specifying the gangue minerals with gilsonite and the manner and extent of their interlocking with gilsonite, + 75 − 420 µm size fraction selected to perform flotation tests. Flotation tests were performed using different reagents including collector (Gas oil, Kerosene and Pine oil), frother (MIBC) and depressant (sodium silicate, tannic acid, sulfuric acid and sodium cyanide) in different dosages. Based on the results, the use of kerosene collector, MIBC frother and a mixture of sodium silicate, tannic acid, sulfuric acid and sodium cyanide depressant had the most favorable results in gilsonite flotation in the rougher stage. Cleaner and recleaner flotation stages for the rougher flotation concentrate resulted in a product with an ash content of 4.89%. Due to the interlocking of gilsonite with impurities in size fractions − 105 µm, it is better to re-grinding the concentrate of the rougher stage beforehand flotation in the cleaner and recleaner stages. Finally, based on the results of mineralogical studies and processing tests, a processing flowsheet including crushing and initial granulation of gilsonite, flotation in rougher, cleaner and recleaner stages has been proposed to produce gilsonite concentrate with < 5% ash content.

  • 12.
    Bahrami, Ataallah
    et al.
    Department of Mining Engineering, Urmia University, Urmia, Iran.
    Mirmohammadi, Mirsaleh
    School of Mining Engineering, College of Engineering, University of Tehran, Tehran, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Kazemi, Fatemeh
    Department of Mining Engineering, Urmia University, Urmia, Iran.
    Abdollahi, Morteza
    Department of Mining Engineering, Urmia University, Urmia, Iran.
    Danesh, Abolfazl
    Complex of Copper Processing-Sungun, East Azerbaijan Province, Tabriz, Iran.
    Process mineralogy as a key factor affecting the flotation kinetics of copper sulfide minerals2019In: International Journal of Minerals, Metallurgy and Materials, ISSN 1674-4799, E-ISSN 1869-103X, Vol. 26, no 4, p. 430-439Article in journal (Refereed)
    Abstract [en]

    The aim of this study is to apply process mineralogy as a practical tool for further understanding and predicting the flotation kinetics of the copper sulfide minerals. The minerals’ composition and association, grain distribution, and liberation within the ore samples were analyzed in the feed, concentrate, and the tailings of the flotation processes with two pulp densities of 25wt% and 30wt%. The major copper-bearing minerals identified by microscopic analysis of the concentrate samples included chalcopyrite (56.2wt%), chalcocite (29.1wt%), covellite (6.4wt%), and bornite (4.7wt%). Pyrite was the main sulfide gangue mineral (3.6wt%) in the concentrates. A 95% degree of liberation with d80 > 80 µm was obtained for chalcopyrite as the main copper mineral in the ore sample. The recovery rate and the grade in the concentrates were enhanced with increasing chalcopyrite particle size. Chalcopyrite particles with a d80 of approximately 100 µm were recovered at the early stages of the flotation process. The kinetic studies showed that the kinetic second-order rectangular distribution model perfectly fit the flotation test data. Characterization of the kinetic parameters indicated that the optimum granulation distribution range for achieving a maximum flotation rate for chalcopyrite particles was between the sizes 50 and 55 µm.

  • 13.
    Barbosa, Leo
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Tiu, Glacialle
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Jansson, Nils F.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Wanhainen, Christina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lilja, Lena
    Garpenberg Mine, Boliden Mineral AB, SE-77698 Garpenberg, Sweden.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Gold mineralization in the Lappberget deposit, Garpenberg mine, Sweden: towards a geometallurgical approach2022In: Geological Society of Sweden, 150 year anniversary meeting: Abstract volume / [ed] Bergman Weihed, J.; Johansson, Å.; Rehnström, E., 2022, p. 116-117Conference paper (Other academic)
    Abstract [en]

    This study investigates the mineralogy and texture of gold-bearing phases in the Lappberget deposit, Garpenberg Mine, and how these characteristics affect gold recovery during mineral processing. Multiple methods such as optical microscopy, SEM-EDS, EPMA, LA-ICP-MS, and bulk chemical analysis were applied on drill core samples, and samples from the processing plant’s Knelson gravity concentrator. Electrum-type alloys were recognized as the most common gold hosts. 

  • 14.
    Bergamo, Pedro A. de S.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Izart, Caroline
    Metso Outotec Oy, Rauhalanpuisto 9, 02230 Espoo, Finland.
    Streng, Emilia S.
    Aalto University, 02150 Espoo, Finland.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Use of Kirkpatrick evaluation model in simulation-based trainings for the mining industry - A case study for froth flotation2022In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 188, article id 107825Article in journal (Refereed)
    Abstract [en]

    Trainings play a vital role in the transference of knowledge between skilled and novice operators in the mineral industry. Evaluation is an important part of those trainings, but many trainings rely solely on the trainees’ feedback. This paper presents how technology enhancement can help produce more effective training evaluations to the mineral industry. It describes a case study involving a froth flotation simulator-based training, including details of the simulation, user interface, and the training program. The training was delivered to sixteen mining operators and evaluated by both the traditional method (trainee&apos;s feedback) and with the simulation&apos;s learning evaluation. The feedback evaluation showed a high level of satisfaction with the learning results, while the learning evaluation showed a very different training outcome, putting established evaluation methods such as Kirckpatrick&apos;s “Four levels” into question. Correlations between the learning results and the operators’ personal information such as process work, and academic experience are also presented.

  • 15.
    Bergamo, Pedro A. de S.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering. Metso Outotec Oyj, Rauhalanpuisto 9, 02230 Espoo, Finland.
    Streng, Emilia S.
    Metso Outotec Oyj, Rauhalanpuisto 9, 02230 Espoo, Finland.
    de Carvalho, Marly A.
    Metso Outotec Oyj, Rauhalanpuisto 9, 02230 Espoo, Finland.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Simulation-based training and learning: A review on technology-enhanced education for the minerals industry2022In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 175, article id 107272Article in journal (Refereed)
    Abstract [en]

    There is a lack of skilled operators for mineral processing plants in the mining sector, which might be related to the challenge of creating trainings that addresses the operator’s daily work problems. In recent years, the use of simulator-based trainings as a tool to build competence has grown in many different fields. With the help of technologies like virtual reality, these tools have been demonstrated to increase awareness and the capability of workers when compared to traditional learning methods. In this paper, a review is presented on the development and application of such technologies in simulation-based training for the training of operators of the minerals industry in the last 20 years. Proposed next steps and new technologies with the potential of improving these applications are also discussed.

  • 16.
    Burnett, Mark
    et al.
    AMC Consultants Limited, UK.
    Zhang, Steven E.
    PG Techno Wox (SmartMin).
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Bourdeau, Julie E.
    PG Techno Wox (SmartMin).
    Steiner, Benedikt M.
    Has 11 years of global experience in project generation. He has an MSc from the Royal School of Mines, London, and a PhD from the University of Exeter. He is currently Director of the Master's Programme in Exploration and Mining Geology at the, Camborne School of Mines, UK.
    Barnet, James S. K.
    St Andrews, Scotland.
    Nwaila, Glen T.
    University of the Witwatersrand.
    Development of mineral supply and demand from 1950 to 2020: Cold War and consumerism2022In: Routledge Handbook of the Extractive Industries and Sustainable Development / [ed] Natalia Yakovleva; Edmund Nickless, Taylor & Francis Group, 2022, p. 34-60Chapter in book (Other academic)
    Abstract [en]

    The supply and demand of minerals from 1950 to 2020 is examined by focusing on known causal relationships and historical drivers such as the Cold War, and how these have impacted the supply and demand of minerals. The complex, and often fascinating, events that have influenced supply and demand in the minerals market, including geopolitics, environmental policy, high-tech modernization, and the COVID-19 pandemic are reviewed. The examples we provide, focus on the primary consumers in the minerals market, including America, the European Union (EU), and the BRICS (Brazil, Russia, India, China, and South Africa) nations. Fundamental drivers such as sustainability, national defence, and technology are also discussed. This chapter begins with an integrated highlight of the major developments from 1950 to 2020 and then expands on the subject matter in a decadal fashion, providing additional context and detail on the forces and events which have influenced mineral supply and consumption trends.

  • 17.
    Chelgani, Saeed Chehreh
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Parian, Mehdi
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Semsari, Parisa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    A comparative study on the effects of dry and wet grinding on mineral flotation separation: a review2019In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 8, no 5, p. 5004-5011Article, review/survey (Refereed)
    Abstract [en]

    Water scarcity dictates to limit the use of water in ore processing plants particularly in arid regions. Since wet grinding is the most common method for particle size reduction and mineral liberation, there is a lack of understanding about the effects of dry grinding on downstream separation processes such as flotation. This manuscript compiles various effects of dry grinding on flotation and compares them with wet grinding. Dry grinding consumes higher energy and produces wider particle size distributions compared with wet grinding. It significantly decreases the rate of media consumption and liner wear; thus, the contamination of pulp for flotation separation is lower after dry grinding. Surface roughness, particle agglomeration, and surface oxidation are higher in dry grinding than wet grinding, which all these effects on the flotation process. Moreover, dry ground samples in the pulp phase correlate with higher Eh and dissolved oxygen concentration. Therefore, dry grinding can alter the floatability of minerals. This review thoroughly assesses various approaches for flotation separation of different minerals, which have been drily ground, and provides perspectives for further future investigations.

  • 18.
    Delavar, Mohammad Amir
    et al.
    Department of Soil Science, University of Zanjan, Zanjan, Iran.
    Naderi, Arman
    Department of Soil Science, University of Zanjan, Zanjan, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Mehrpouyan, Ahmad
    Department of Chemistry, University of Zanjan, Zanjan, Iran.
    Bakhshi, Ali
    Department of Electrical Engineering, Faculty of Electrical and Computer Engineering, Institute of Ghiaseddin Jamshid Kashani, Qazvin, Iran.
    Soil salinity mapping by remote sensing south of Urmia Lake, Iran2020In: Geoderma Regional, ISSN 2352-0094, Vol. 22, article id e00317Article in journal (Refereed)
    Abstract [en]

    Urmia Lake is a shallow terminal Lake located in northwest Iran and it is one of the largest permanent Lakes in the Middle East. In this study, the changes in soil salinity at Urmia Lake were investigated using satellite images and the oldest salinity map of the area over a period of 45 years from 1973 to 2018. The distribution of salinity in 2018 was estimated using the supervised classification by the nonlinear hybrid model of artificial multi-layered neural network-genetic algorithm model (ANN-GA) while the salinity map for the years of 1985, 1995, 2005 and 2015 was estimated by the unsupervised method. Further, the salinity data of surface soil in the region for the year 1973 was also digitized and utilized. For this purpose, 291 surface samples (258 samples for modeling and 33 samples for the re-evaluation of the model) of the studied region were collected and analyzed in 2018. The input neurons were selected by analyzing the satellite imagery bands, salinity indices, salinity ratio index and normalized difference vegetation index. The correlation coefficient and root-mean-square error of the training network model were equal to 0.94 and 0.04, respectively. The salinity map of the studied region was estimated using this model and classified into six classes (S0 to S5). The produced map of 2018 was used to re-evaluate the results. It showed that lower estimation accuracy was in classes S1 and S2. The obtained results in this study indicated that roughness, moisture, the density of halophyte plants and sodium slickspot were some of the sources for estimation of errors in lower salinity classes. The time-series changes in the salinity class of estimated maps showed that S3, S4 and S5 classes have expanded between 1973 and 2018. These are in agreement with the field observation and with the other scientific reports about the studied area.

  • 19.
    Ghorbani, Yousef
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Nwaila, Glen T.
    School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa.
    Chirisa, Munyar
    Deloitte LLP, Toronto, Ontario, Canada.
    Systematic Framework toward a Highly Reliable Approach in Metal Accounting2022In: Mineral Processing and Extractive Metallurgy Review, ISSN 0882-7508, E-ISSN 1547-7401, Vol. 43, no 5, p. 664-678Article in journal (Refereed)
    Abstract [en]

    Metal accounting is becoming an area of growing focus because of the requirement for the resulting data to feed directly into financial reports. It is vital in the fulfillment of best corporate governance practices and to provide assurance on metallurgical processes. The current metal accounting practices deliver a number of important measures, but an essential change in the approach toward data integrated and auditable metal accounting system is an indispensable need. This work aims to present a systematic framework toward a highly reliable method in mental accounting. The proposed approach introduces a novel mining to product metal accounting scheme and conceptualization of an intelligent metallurgical and metal accounting information management system (MMAIMS). An open cast gold mine in South Africa is presented as a case study. Based on the results and discussions that we have presented in this study, it has been shown that the proposed intelligent MMAIMS will result in improved plant process control, transparent financial reporting, and a suitable understanding of interrelationships between different process activities. The intelligent MMAIMS approach will eradicate data security risks related to multiple-user environment spreadsheets, create reliability in data used for decision-making and operation data synchronization. End to end metal accounting process visibility across the whole process will advance the audibility and transparency of metal accounting from mine to product, and enable good corporate governance and financial reporting of the salable metal product concerning smart mining and mineral processing concept.

  • 20.
    Ghorbani, Yousef
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering. School of Chemistry, University of Lincoln, Lincoln, LN6 7TS, UK.
    Nwaila, Glen T.
    Wits Mining Institute, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg, 2000, South Africa; Wits Mining Institute, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa.
    Zhang, Steven E.
    Wits Mining Institute, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg, 2000, South Africa; Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E8, Canada; SmartMin Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Bourdeau, Julie E.
    Wits Mining Institute, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg, 2000, South Africa; Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E8, Canada; SmartMin Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Cánovas, Manuel
    Department of Metallurgical and Mining Engineering, Universidad Catolica del Norte, Antofagasta, Chile.
    Arzua, Javier
    Department of Metallurgical and Mining Engineering, Universidad Catolica del Norte, Antofagasta, Chile.
    Nikadat, Nooraddin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Moving towards deep underground mineral resources: Drivers, challenges and potential solutions2023In: Resources policy, ISSN 0301-4207, E-ISSN 1873-7641, Vol. 80, article id 103222Article in journal (Refereed)
    Abstract [en]

    Underground mining has historically occurred in surface and near-surface (shallow) mineral deposits. While no universal definition of deep underground mining exists, humanity's need for non-renewable natural resources has inevitably pushed the boundaries of possibility in terms of environmental and technological constraints. Recently, deep underground mining is being extensively developed due to the depletion of shallow mineral deposits. One of the main advantages of deep underground mining is its lower environmental footprint compared to shallow mining. In this paper, we summarise the key factors driving deep underground mining, which include an increasing need for raw materials, exhaustion of shallow mineral deposits, and increasing environmental scrutiny. We examine the challenges associated with deep underground mining, mainly the: environmental, financial, geological, and geotechnical aspects. Furthermore, we explore solutions provided by recent advances in science and technology, such as the integration of mineral processing and mining, and the digital and technological revolution. We further examine the role of legacy data in its ability to bridge current and future practices in the context of deep underground mining.

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  • 21.
    Ghorbani, Yousef
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Nwaila, Glen T.
    School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa.
    Zhang, Steven E.
    PG Techno Wox, 43 Patrys Avenue, Helikon Park, Randfontein 1759, South Africa.
    Hay, Martyn P.
    Eurus Mineral Consultants (EMC), Plettenberg Bay, South Africa.
    Repurposing legacy metallurgical data part II: Case studies of plant performance optimisation and process simulation2021In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 160, article id 106667Article in journal (Refereed)
    Abstract [en]

    The history of the metallurgical industry is rich with data. An enormous amount of data is generated from mining operations and industrial factories, and as deployment of new technologies such as on-line monitoring and in-situ instrumentation proliferate through the 4th industrial revolution, the quantity and quality of data will increase dramatically. The first paper (Part I), describes a range of promising technologies that integrate well with existing mineral processing plants and testing laboratories to demonstrate the enormous potential of a dry laboratory. A dry lab is a type of laboratory that includes applied or computational mathematical analyses for an extensive range of different applications. In both laboratories and mineral processing plants, integration of timely, accurate and reliable data analytics is key to leveraging data to enable data-driven plant design, optimisation and monitoring. However and despite progresses in analytical technology and increasing availability of data and sophisticated data analytics, legacy metallurgical plant and test work data are being underutilised. Understanding the insights contained within legacy metallurgical plant data is critical to the transition into a data- and analytics-driven industry. This paper (Part II) details two case studies that use legacy data to benefit metallurgical processes. One case study focuses on operational data from a gold recovery plant and provide indirect knowledge of the structure and/or composition of the feed sources, and insights to guide the optimisation of the operation. The other case study focuses on laboratory flotation tests, and demonstrates the effectiveness of aggregated data in establishing empirical guidelines that can guide the design and optimisation of new and existing processing operations.

  • 22.
    Ghorbani, Yousef
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Nwaila, Glen T.
    School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa.
    Zhang, Steven E.
    PG Techno Wox, 43 Patrys Avenue, Helikon Park, Randfontein 1759, South Africa.
    Hay, Martyn P.
    Eurus Mineral Consultants (EMC), Plettenberg Bay, South Africa.
    Bam, Lunga C.
    Department Radiation Science, Necsa, PO Box 582, Pretoria, South Africa.
    Guntoro, Pratama Istiadi
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Repurposing legacy metallurgical data Part I: A move toward dry laboratories and data bank2020In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 159, article id 106646Article, review/survey (Refereed)
    Abstract [en]

    Advancements in modern mineral processing has been driven by technology and fuelled by market economics of supply and demand. Over the last three decades, the demand for various minerals has steadily increased, while the mineral processing industry has seen an unavoidable increase in the treatment of complex ores, continuous decline in plant feed grade and poor plant performance partly due to blending of ores with dissimilar properties. Despite these challenges, production plant data that are routinely generated are usually underutilised. In this contribution and aligned with the direction of the 4th industrial revolution, we highlight the value of legacy metallurgical plant data and the concept of a dry laboratory approach. This study is presented in two parts. In the current paper (Part I), a comprehensive review of the potential for the combination of modern analytical technology with data analytics to generate a new competence for process optimisation are provided. To demonstrate the value of data within the extractive metallurgy discipline, we employ data analytics and simulation to examine gold plant performance and the flotation process in two separate case studies in the second paper (Part II). This was done with the aim of showcasing relevant plant data insights, and extract parameters that should be targeted for plant design and performance optimisation. We identify several promising technologies that integrate well with existing mineral processing plants and testing laboratories to exploit the concept of a dry laboratory, in order to enhance pre-existing mineral processing chains. It also sets the passage in terms of the value of innovative analysis of existing and simulation data as part of the new world of data analytics. Using data- and technology-driven initiatives, we propose the establishment of dry laboratories and data banks to ultimately leverage integrated data, analytics and process simulation for effective plant design and improved performance.

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  • 23.
    Ghorbani, Yousef
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Nwaila, Glen T.
    School of Geosciences, University of the Witwatersrand, Wits, South Africa.
    Zhang, Steven E.
    PG Techno Wox, Randfontein, South Africa.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Rethinking Mineral Processing and Extractive Metallurgy Approaches to Ensure a Sustainable Supply of High-tech and Critical Raw Materials2021In: Rare Metal Technology 2021 / [ed] Gisele Azimi, Takanari Ouchi, Kerstin Forsberg, Hojong Kim, Shafiq Alam, Alafara Abdullahi Baba, Neale R. Neelameggham, Springer, 2021, p. 173-186Conference paper (Refereed)
    Abstract [en]

    Raw materials (RM) are crucial for maintaining our standard of living internationally. The fourth industrial revolution and the energy transition are reliant on access to various RMs. High-tech RMs are usually extracted as by-products from ore deposits. To increase the production of rare high-tech RM, it is essential to modify the existing bulk RM production processes and utilize partial, secondary, or waste streams. This study aims to present and discuss the necessities of redefining the concept and scope in mineral processing and extractive metallurgy approaches in order to secure a sustainable supply of high-tech and critical raw material (CRM) for the economy in modern society. We introduce a list of paths and trends for developing future concepts and methods in mineral processing and extractive metallurgy in pursuit of the sustainability of high-tech CRMs from all resources.

  • 24.
    Ghorbani, Yousef
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Zhang, Steven E.
    PG Techno Wox (Pty) Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa; Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E9, Canada.
    Nwaila, Glen T.
    Wits Mining Institute (WMI), University of the Witwatersrand, Private Bag 3, 2050 Wits, South Africa.
    Bourdeau, Julie E.
    Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E9, Canada.
    Framework components for data-centric dry laboratories in the minerals industry: A path to science-and-technology-led innovation2022In: The Extractive Industries and Society, ISSN 2214-790X, E-ISSN 2214-7918, Vol. 10, article id 101089Article, review/survey (Refereed)
    Abstract [en]

    The world continues to experience a surge in data generation and digital transformation. Historic data is increasingly being replaced by modernized data, such as big data, which is regarded as data that exhibits the 5Vs: volume, variety, velocity, veracity and value. The capacity to optimally use and comprehend value from big data has become an indispensable aptitude for modern companies. In contrast to commercial and technology firms, usage, management and governance of data, including big data is a novel and evolving trend for mining and mineral industries. Although the mining industry can be unenthusiastic to change, embracing modernized data and big data is evolutionarily unavoidable, given many industry-wide challenges (i.e., fluctuation in commodity prices, geotechnical and harsh ground conditions, and ore grade), which corrode revenues and increase business risks, including the possibility of regulatory non-compliance. The minerals industry holds a genuine gold mine of data that were collected for scientific, engineering, operational and other purposes. Data and data-centric workspaces that are targeted towards innovation and experimentation, which if combined with in-discipline expertise are two harmonious ingredients that can provide many practical solutions for the mining and mineral industries. In this paper, the concept, the opportunity and the necessity for a move towards a technology- and innovation-based, data-centric ‘dry laboratories’ (common workspaces that facilitates data-centric experimentation and innovation) in the minerals industry are assessed. We contend that the dry laboratory environment maximizes the value of data for the minerals industry. Toward the establishment of dry laboratories, we propose several essential components of a framework that would enable the functionality of dry laboratories in the minerals industry, while concomitantly examining the components from both academia and industry perspectives.

  • 25.
    Ghorbani, Yousef
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Zhang, Steven E.
    Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada; Wits Mining Institute, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa.
    Nwaila, Glen T.
    Wits Mining Institute, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa; School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa.
    Bourdeau, Julie E.
    Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada; Wits Mining Institute, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa.
    Safari, Mehdi
    Minerals Processing Division, Mintek, Private Bag X3015, Randburg 2125, South Africa.
    Hadi Hoseinie, Seyed
    Department of Mining Engineering, Isfahan University of Technology, Isfahan, Iran.
    Nwaila, Phumzile
    PG Techno Wox (Pty) Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Ruuska, Jari
    Faculty of Technology, Control Engineering, University of Oulu, Finland.
    Dry laboratories – Mapping the required instrumentation and infrastructure for online monitoring, analysis, and characterization in the mineral industry2023In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 191, article id 107971Article, review/survey (Refereed)
    Abstract [en]

    Dry laboratories (dry labs) are laboratories dedicated to using and creating data (they are data-centric). Several aspects of the minerals industry (e.g., exploration, extraction and beneficiation) generate multi-scale and multivariate data that are ultimately used to make decisions. Dry labs and digitalization are closely and intricately linked in the minerals industry. This paper focuses on the instrumentation and infrastructure that are required for accelerating digital transformation initiatives in the minerals sector. Specifically, we are interested in the ability of current and emerging instrumentation, sensors and infrastructure to capture relevant information, generate and transport high-quality data. We provide an essential examination of existing literature and an understanding of the 21st century minerals industry. Critical analysis of the literature and review of the current configuration of the minerals industry revealed similar data management and infrastructure needs for all segments of the minerals industry. There are, however, differences in the tools and equipment used at different stages of the mineral value chain. As demand for data-driven approaches grows, and as data resulting from each segment of the minerals industry continues to increase in abundance, diversity and dimensionality, the tools that manage and utilize such data should evolve in a way that is more transdisciplinary (e.g., data management, artificial intelligence, machine learning and data science). Ideally, data should be managed in a dry lab environment, but minerals industry data is currently and historically disaggregated. Consequently, digitalization in the minerals industry must be coupled with dry laboratories through a systematic transition. Sustained generation of high-quality data is critical to sustain the highly desirable uses of data, such as artificial intelligence-based insight generation.

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  • 26.
    Guntoro, Pratama Istiadi
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Butcher, Alan R.
    Geological Survey of Finland GTK, PO Box 96, 02151, Espoo, Finland.
    Kuva, Jukka
    Geological Survey of Finland GTK, PO Box 96, 02151, Espoo, Finland.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Textural Quantification and Classification of Drill Cores for Geometallurgy: Moving Toward 3D with X-ray Microcomputed Tomography (µCT)2020In: Natural Resources Research, ISSN 1520-7439, E-ISSN 1573-8981, Vol. 29, no 6, p. 3547-3565Article in journal (Refereed)
    Abstract [en]

    Texture is one of the critical parameters that affect the process behavior of ore minerals. Traditionally, texture has been described qualitatively, but recent works have shown the possibility to quantify mineral textures with the help of computer vision and digital image analysis. Most of these studies utilized 2D computer vision to evaluate mineral textures, which is limited by stereological error. On the other hand, the rapid development of X-ray microcomputed tomography (µCT) has opened up new possibilities for 3D texture analysis of ore samples. This study extends some of the 2D texture analysis methods, such as association indicator matrix (AIM) and local binary pattern (LBP) into 3D to get quantitative textural descriptors of drill core samples. The sensitivity of the methods to textural differences between drill cores is evaluated by classifying the drill cores into three textural classes using methods of machine learning classification, such as support vector machines and random forest. The study suggested that both AIM and LBP textural descriptors could be used for drill core classification with overall classification accuracy of 84–88%.

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  • 27.
    Guntoro, Pratama Istiadi
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Koch, Pierre-Henri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    X-ray Microcomputed Tomography (µCT) for Mineral Characterization: A Review of Data Analysis Methods2019In: Minerals, E-ISSN 2075-163X, Vol. 9, no 3, article id 183Article in journal (Refereed)
    Abstract [en]

    The main advantage of X-ray microcomputed tomography (µCT) as a non-destructive imaging tool lies in its ability to analyze the three-dimensional (3D) interior of a sample, therefore eliminating the stereological error exhibited in conventional two-dimensional (2D) image analysis. Coupled with the correct data analysis methods, µCT allows extraction of textural and mineralogical information from ore samples. This study provides a comprehensive overview on the available and potentially useful data analysis methods for processing 3D datasets acquired with laboratory µCT systems. Our study indicates that there is a rapid development of new techniques and algorithms capable of processing µCT datasets, but application of such techniques is often sample-specific. Several methods that have been successfully implemented for other similar materials (soils, aggregates, rocks) were also found to have the potential to be applied in mineral characterization. The main challenge in establishing a µCT system as a mineral characterization tool lies in the computational expenses of processing the large 3D dataset. Additionally, since most of the µCT dataset is based on the attenuation of the minerals, the presence of minerals with similar attenuations limits the capability of µCT in mineral segmentation. Further development on the data processing workflow is needed to accelerate the breakthrough of µCT as an analytical tool in mineral characterization.

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  • 28.
    Guntoro, Pratama Istiadi
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Parian, Mehdi
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Butcher, Alan R.
    Geological Survey of Finland GTK, PO Box 96, 02151 Espoo, Finland.
    Kuva, Jukka
    Geological Survey of Finland GTK, PO Box 96, 02151 Espoo, Finland.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Development and experimental validation of a texture-based 3D liberation model2021In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 164, article id 106828Article in journal (Refereed)
    Abstract [en]

    Prediction of mineral liberation is one of the key steps in establishing a link between ore texture and its processing behavior. With the rapid development of X-ray Microcomputed Tomography (µCT), the extension of liberation modeling into 3D realms becomes possible. Liberation modeling allows for the generation of particle population from 3D texture data in a completely non-destructive manner. This study presents a novel texture-based 3D liberation model that is capable of predicting liberation from 3D drill core image acquired by µCT. The model takes preferential, phase-boundary, and random breakage into account with differing relative contributions to the liberation depending on the ore texture itself. The model was calibrated using experimental liberation data measured in 3D µCT. After calibration, the liberation model was found to be capable of explaining on average of around 84% of the variance in the experimental liberation data. The generated particle population can be used for particle-based process simulation to evaluate the process responses of various ore textures subjected to various modes of breakage.

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  • 29.
    Guntoro, Pratama Istiadi
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering. Kaunis Iron AB, Bert-Ove Johanssons väg 8, SE-984 91, Pajala, Sweden.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    3D Ore Characterization as a Paradigm Shift for Process Design and Simulation in Mineral Processing2021In: Berg- und Huttenmännische Monatshefte (BHM), ISSN 0005-8912, E-ISSN 1613-7531, Vol. 166, no 8, p. 384-389Article in journal (Refereed)
    Abstract [en]

    Current advances and developments in automated mineralogy have made it a crucial key technology in the field of process mineralogy, allowing better understanding and connection between mineralogy and the beneficiation process. The latest developments in X‑ray micro-computed tomography (µCT) have shown a great potential to let it become the next-generation automated mineralogy technique. µCT’s main benefit lies in its capability to allow 3D monitoring of the internal structure of the ore sample at resolutions down to a few hundred nanometers, thus excluding the common stereological error in conventional 2D analysis. Driven by the technological and computational progress, µCT is constantly developing as an analysis tool and successively it will become an essential technique in the field of process mineralogy. This study aims to assess the potential application of µCT systems, for 3D ore characterization through relevant case studies. The opportunities and platforms that µCT 3D ore characterization provides for process design and simulation in mineral processing are presented.

  • 30.
    Guntoro, Pratama Istiadi
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Use of X-ray Micro-computed Tomography (µCT) for 3-D Ore Characterization: A Turning Point in Process Mineralogy2019In: IMCET 2019 - Proceedings of the 26th International Mining Congress and Exhibition of Turkey, Baski , 2019, p. 1044-1054Conference paper (Refereed)
    Abstract [en]

    In recent years, automated mineralogy has become an essential enabling technology in the field of process mineralogy, allowing better understanding between mineralogy and the beneficiation process. Recent developments in X-ray micro-computed tomography (μCT) as a non-destructive technique have indicated great potential to become the next automated mineralogy technique. μCT’s main advantage lies in its ability to allow 3-D monitoring of internal structure of the ore at resolutions down to a few hundred nanometers, thereby eliminating the stereological error encountered in conventional 2-D analysis. Driven by the technological and computational progress, the technique is continuously developing as an analysis tool in ore characterization and subsequently it foreseen thatμCT will become an indispensable technique in the field of process mineralogy. Although several software tools have been developed for processing μCT dataset, but the main challenge in μCT data analysis remains in the mineralogical analysis, where μCT data often lacks contrast between mineral phases, making segmentation difficult. In this paper, an overview of some current applications of μCT in ore characterization is reviewed, alongside with it potential implications to process mineralogy. It also describes the current limitations of its application and concludes with outlook on the future development of 3-D ore characterization.

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  • 31.
    Guntoro, Pratama Istiadi
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Tiu, Glacialle
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Lund, Cecilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Application of machine learning techniques in mineral phase segmentation for X-ray microcomputed tomography (µCT) data2019In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 142, article id 105882Article in journal (Refereed)
    Abstract [en]

    X-ray microcomputed tomography (µCT) offers a non-destructive three-dimensional analysis of ores but its application in mineralogical analysis and mineral segmentation is relatively limited. In this study, the application of machine learning techniques for segmenting mineral phases in a µCT dataset is presented. Various techniques were implemented, including unsupervised classification as well as grayscale-based and feature-based supervised classification. A feature matching method was used to register the back-scattered electron (BSE) mineral map to its corresponding µCT slice, allowing automatic annotation of minerals in the µCT slice to create training data for the classifiers. Unsupervised classification produced satisfactory results in terms of segmenting between amphibole, plagioclase, and sulfide phases. However, the technique was not able to differentiate between sulfide phases in the case of chalcopyrite and pyrite. Using supervised classification, around 50–60% of the chalcopyrite and 97–99% of pyrite were correctly identified. Feature based classification was found to have a poorer sensitivity to chalcopyrite, but produced a better result in segmenting between the mineral grains, as it operates based on voxel regions instead of individual voxels. The mineralogical results from the 3D µCT data showed considerable difference compared to the BSE mineral map, indicating stereological error exhibited in the latter analysis. The main limitation of this approach lies in the dataset itself, in which there was a significant overlap in grayscale values between chalcopyrite and pyrite, therefore highly limiting the classifier accuracy.

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  • 32.
    Hernández, Pía
    et al.
    Departamento de Ingeniería Química y Procesos de Minerales, Universidad de Antofagasta, Antofagasta, Chile..
    Dorador, Alexis
    Departamento de Ingeniería Química y Procesos de Minerales, Universidad de Antofagasta, Antofagasta, Chile..
    Martínez, Monserrat
    Departamento de Ingeniería Química y Procesos de Minerales, Universidad de Antofagasta, Antofagasta, Chile..
    Toro, Norman
    Faculty of Engineering and Architecture, Universidad Arturo Prat, Antofagasta, Chile. Departamento de Ingeniería en Metalurgia y Minas, Universidad Católica del Norte, Av. Angamos 0610, Antofagasta, Chile..
    Castillo, Jonathan
    Departamento de Ingeniería en Metalurgia, Universidad de Atacama, Copiapó, Chile..
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Use of Seawater/Brine and Caliche’s Salts as Clean and Environmentally Friendly Sources of Chloride and Nitrate Ions for Chalcopyrite Concentrate Leaching2020In: Minerals, E-ISSN 2075-163X, Vol. 10, no 5, article id 477Article in journal (Refereed)
    Abstract [en]

    A less harmful approach for the environment regarding chalcopyrite concentrate leaching,using seawater/brine and caliche’s salts as a source of chloride and nitrate ions, was investigated.Dierent variables were evaluated: sulfuric acid concentration, sodium nitrate concentration, chlorideconcentration, source of water (distilled water, seawater, and brine), temperature, concentrate sampletype, nitrate source (analytical grade and industrial salt), and pre-treatment methods in order toobtain maximum copper extraction. All tests were performed at moderate temperatures (45 C)and atmospheric pressure. The leaching system using distilled water, seawater, and brine basemedia resulted in copper extraction of 70.9%, 90.6%, and 86.6% respectively. The leaching media,with a concentration of 20 g/L Cl􀀀, obtained a maximum Cu extraction of 93.5%. An increase in theconcentration of H2SO4 and NaNO3 from 0.5 to 0.7 M, led to an increase in the copper extraction.The use of an industrial salt compared to the analytical salt did not show great variations in thepercentage of extraction achieved, which would be a good and cost eective alternative. The increasein temperature from 25 to 45 C showed a great eect on the copper leaching (of 60% until 90.6%,respectively). The pre-treatment is suggested to increase copper extraction from 60.0% to 71.4%.

  • 33.
    How Kuan, Seng
    et al.
    Department of Mechanical and Material Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Kajang, Selangor, Malaysia.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Chieng, Sylvia
    Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia.
    Narrowing the gap between local standards and global best practices inbauxite mining: A case study in Malaysia2020In: Resources policy, ISSN 0301-4207, E-ISSN 1873-7641, Vol. 66, article id 101636Article in journal (Refereed)
    Abstract [en]

    In mining the concept of sustainable development often encounters a paradoxical meaning as numerous mines in the past have closed due to exhausted amounts of ores. Despite the paradox, sustainable development and mining can be made compatible, if mining activities are carried out responsibly and sustainably. This holds true especially in the developing world where illegal and unregulated mining is still being practiced. In Malaysia, annual production of bauxite ore increased drastically from 208,770 tonnes in 2013, to 962,799 tonnes in 2014. The increase stemmed primarily from Indonesia banning exports of bauxite in 2014 to boost its own aluminium smelting industry. This led China to suffer low bauxite supply to meet its national aluminium production demand. Subsequently, mining companies flocked to the hills around Kuantan, Malaysia which host large amounts of low-grade bauxite where the ore is procured and exported to China via seaway. The immediate spike in bauxite production came with environmental and health consequences for residents due to unregulated rampant mining. Consequently, the authorities imposed a temporary moratorium on bauxite mining from Jan 15, 2016 with exceptions for exports of stockpiled bauxite. As a result, production in 2016 dropped to 342,924 tonnes from a peak of 7,164,956 tonnes in 2015. After extending the moratorium nine times, the government announced recently that there would be no further extension and mining could resume in April 2019 with new standard operating procedures (SOP). This work analyses the gap between local standards and global best practices and discovers a disconnect between the two, largely centred around the area of environmental management and performance. The work also elucidates the weaknesses in the current SOP and strategies are proposed to resolve these shortcomings. Recommendations are made to bring Malaysian bauxite mining practices to international standards by stressing on improved sustainability indicators, policy provisions and data transparency.

  • 34.
    Ilankoon, I.M.S.K
    et al.
    Discipline of Chemical Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia. Global Asia in the 21st Century (GA21) Multidisciplinary Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Nan Chong, Meng
    Discipline of Chemical Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia. Global Asia in the 21st Century (GA21) Multidisciplinary Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia. Sustainable Water Alliance, Advanced Engineering Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia.
    Herath, Gamini
    Global Asia in the 21st Century (GA21) Multidisciplinary Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia. School of Business, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia.
    Moyo, Thandazile
    Department of Chemical Engineering, University of Cape Town, Rondebosch, South Africa.
    Petersen, Jochen
    Department of Chemical Engineering, University of Cape Town, Rondebosch, South Africa.
    E-waste in the international context: A review of trade flows, regulations, hazards, waste management strategies and technologies for value recovery2018In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 82, p. 258-275Article in journal (Refereed)
    Abstract [en]

    E-waste, or waste generated from electrical and electronic equipment, is considered as one of the fastest-growing waste categories, growing at a rate of 3–5% per year in the world. In 2016, 44.7 million tonnes of e-waste were generated in the world, which is equivalent to 6.1 kg for each person. E-waste is classified as a hazardous waste, but unlike other categories, e-waste also has significant potential for value recovery. As a result it is traded significantly between the developed and developing world, both as waste for disposal and as a resource for metal recovery. Only 20% of global e-waste in 2016 was properly recycled or disposed of, with the fate of the remaining 80% undocumented – likely to be dumped, traded or recycled under inferior conditions. This review paper provides an overview of the global e-waste resource and identifies the major challenges in the sector in terms of generation, global trade and waste management strategies. It lists the specific hazards associated with this type of waste that need to be taken into account in its management and includes a detailed overview of technologies employed or proposed for the recovery of value from e-waste. On the basis of this overview the paper identifies future directions for effective e-waste processing towards sustainable waste/resource management. It becomes clear that there is a strong divide between developed and developing countries with regard to this sector. While value recovery is practiced in centralised facilities employing advanced technologies in a highly regulated industrial environment in the developed world, in the developing world such recovery is practiced in a largely unregulated artisanal industry employing simplistic, labour intensive and environmentally hazardous approaches. Thus value is generated safely in the hi-tech environment of the developed world, whereas environmental burdens associated with exported waste and residual waste from simplistic processing remain largely in developing countries. It is argued that given the breadth of available technologies, a more systematic evaluation of the entire e-waste value chain needs to be conducted with a view to establishing integrated management of this resource (in terms of well-regulated value recovery and final residue disposal) at the appropriately local rather than global scale.

  • 35.
    Jannesar Niri, Anahita
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Poelzer, Gregory A.
    Luleå University of Technology, Department of Social Sciences, Technology and Arts, Social Sciences.
    Zhang, Steven E.
    Independent Researcher, 39 Kiewiet Street, Helikon Park, Randfontein, 1759, South Africa.
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Pettersson, Maria
    Luleå University of Technology, Department of Social Sciences, Technology and Arts, Social Sciences.
    Ghorbani, Yousef
    School of Chemistry, University of Lincoln, Joseph Banks Laboratories, Green Lane, Lincoln, Lincolnshire, LN6 7DL, United Kingdom.
    Sustainability challenges throughout the electric vehicle battery value chain2024In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 191, article id 114176Article, review/survey (Refereed)
    Abstract [en]

    The global commitment to decarbonizing the transport sector has resulted in an unabated growth in the markets for electric vehicles and their batteries. Consequently, the demand for battery raw materials is continuously growing. As an illustration, to meet the net-zero emissions targets, the electric vehicle market demand for lithium, cobalt, nickel, and graphite will increase 26-times, 6-times, 12-times, and 9-times respectively between 2021 and 2050. There are diverse challenges in meeting this demand, requiring the world to embrace technological and knowledge advancements and new investments without provoking conflicts between competing goals. The uncertainties in a sustainable supply of battery minerals, environmental, social and governance complexities, and geopolitical tensions throughout the whole battery value chain have shaped the global and regional concerns over the success of transport decarbonization. Here, focusing on the entire value chain of electric vehicle batteries, the approaches adopted by regulatory agencies, governments, mining companies, vehicle and battery manufacturers, and all the other stakeholders are evaluated. Bringing together all these aspects, this literature review broadens the scope for providing multifaceted solutions necessary to optimize the goal of transport decarbonization while upholding sustainability criteria. Consolidating the previously fragmented information, a solid foundation for more in-depth research on existing difficulties encountered by governmental and industrial actors is created. The outcomes of this study may serve as a baseline to develop a framework for a climate smart and resource efficient supply of batteries considering the unique impacts of individual players.

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  • 36.
    Kazemi, Fatemeh
    et al.
    Faculty of Engineering, University of Kashan, Kashan, Iran.
    Bahrami, Ataallah
    Department of Mining Engineering, Faculty of Engineering, Urmia University, Urmia, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Danesh, Abolfazl
    Complex of Copper Processing – Sungun, East Azerbaijan Province, Headquarters Rd, Tabriz, Iran.
    Abdollahi, Morteza
    Faculty of Engineering, Isfahan University of Technology, Isfahan, Iran.
    Falah, Hadi
    Department of Mining Engineering, Faculty of Engineering, Urmia University, Urmia, Iran.
    Salehi, Mohsen
    Department of Mining Engineering, Faculty of Engineering, Urmia University, Urmia, Iran.
    The interaction and synergic effect of particle size on flotation efficiency: A comparison study of recovery by size, and by liberation between lab and industrial scale data: [Sinergijski utjecaj djelovanja veličine zrna na učinkovitost flotacije: usporedba laboratorijskih i industrijskih podataka o iskorištenju korisne komponente u koncentratu ovisno o veličini zrna i raščinu (stupnju oslobođenja)]2023In: Rudarsko-Geološko-Naftni Zbornik, ISSN 0353-4529, E-ISSN 1849-0409, Vol. 38, no 1, p. 1-12Article in journal (Refereed)
    Abstract [en]

    The interaction and synergic effect of particle size on flotation efficiency were investigated by a comparison study between laboratories (size-by-size flotation modes) and industrial scale operational data (whole mixed size fraction). For this purpose, sampling was done from the feed, concentrate, and tailing of the flotation rougher cells of the Sungun copper processing complex (located in the northwest of Iran). In the size-by-size flotation mode (lab scale), the sample was first subjected to different size fractions, and then flotation tests were performed for each fraction. On an industrial scale, the particle size distribution of feed, concentrate, and tailing of flotation of the rougher stage have been analyzed. According to the results, in the case of industrial flotation mode (whole mixed size fraction), the particles with d80=84 μm were more likely to reach the tailing of flotation, and the particles within the size range of +63-180 μm constituted the highest amount of concentrate particles. In lab flotation mode (size-by-size), the maximum recovery was in the size fraction of +40-60 μm. By comparing the two flotation modes of industrial (whole mixed size fraction) and lab (size-by-size), for fractions <45 μm, the industrial flotation recovery was approximately 40% greater than the lab flotation recovery. However, for fractions >125 μm, the recovery trend was reversed and the lab flotation recovery was greater than the industrial flotation recovery. Coarse particle flotation has significant economic and technological benefits. By improving the recovery of coarse particles during the flotation process, the amount of grinding requirements will be reduced and consequently, it will considerably decrease the amount of energy consumption.

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  • 37.
    Leiva, Claudio A.
    et al.
    Department of Chemical Engineering, Universidad Católica del Norte, Chile.
    Arcos, Katheryn V.
    Department of Chemical Engineering, Universidad Católica del Norte, Chile.
    Poblete, Diego A.
    Department of Chemical Engineering, Universidad Católica del Norte, Chile.
    Serey, Eduardo A.
    Department of Chemical Engineering, Universidad Católica del Norte, Chile.
    Torres, Cynthia M.
    Department of Metallurgical and Mining Engineering, Universidad Católica del Norte, Chile.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Design and Evaluation of an Expert System in a Crushing Plant2018In: Minerals, E-ISSN 2075-163X, Vol. 8, no 10, article id 469Article in journal (Refereed)
    Abstract [en]

    This document presents a proposal for designing an expert system in the Gabriela Mistral Division’s crushing plant belonging to Codelco (Chile) with the objective of maximizing stacked tonnage, allowing the improvement of operational variables that directly interact with the crushing process. In addition, this study considers the impact that occurs in both the process and operational continuity regarding the standardization of the system. In the first stage, a survey and analysis of historic operation data was carried out, which allowed the definition of benchmarking indicators. Subsequently, both modalities of operation were compared, monitoring processed tonnage and detentions related to operational failures. As a result, significant differences were observed in the performance of the critical line operating with expert control, with a 55% reduction in the detentions referred to operational failures. Added to this is the benefit of low cost and improved quality as the control provides an analysis of the variables in reduced time intervals, which is superior to human control.

  • 38.
    Lishchuk, Viktor
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering. Metso Sweden AB, Sala, Sweden.
    Koch, Pierre-Henri
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Butcher, Alan R.
    eological Survey of Finland/Geologian tutkimuskeskus, Espoo, Finland.
    Towards integrated geometallurgical approach: Critical review of current practices and future trends2020In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 145, article id 106072Article, review/survey (Refereed)
    Abstract [en]

    Geometallurgy has become an important tool for mitigating production risks and improving economic performance in the modern mining industry. Multiple definitions and visions of geometallurgy have been proposed during the last decades. Most of them define geometallurgy as a bridge between geology and mineral processing. Such a definition is rather confusing since process mineralogy claims to be such “bridge” too. Therefore, the main objective of the present paper is to provide a broad image of geometallurgy covering planning, executing and evaluation of geometallurgical programs. Such a vision of geometallurgy was developed within a research project PREP, which was aimed at “resource effective mineral processing”. PREP is a holistic geometallurgical approach independent of deposit type. The approach differentiates geometallurgical programs based on the complexity of the problem and the desirable outcome. Particular attention was paid to the planning of the geometallurgical programs, data management, and new tools development. The practical usage of the approach was tested with three case studies: iron-apatite ore, VMS, and Cu porphyry deposits. Some examples of applying geometallurgy for the iron-apatite ore are shown in this paper. The result, the guidelines on planning, executing and evaluating a geometallurgical program, are given in this paper.

  • 39.
    Lishchuk, Viktor
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Lund, Cecilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Evaluation and comparison of different machine-learning methods to integrate sparse process data into a spatial model in geometallurgy2019In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 134, p. 156-165Article in journal (Refereed)
    Abstract [en]

    A spatial model for process properties allows for improvedproduction planning in mining by considering the process variability ofthe deposit. Hitherto, machine-learning modelling methods have beenunderutilised for spatial modelling in geometallurgy. The goal of thisproject is to find an efficient way to integrate process properties (ironrecovery and mass pull of the Davis tube, iron recovery and mass pull ofthe wet low intensity magnetic separation, liberation of iron oxides, andP_80) for an iron ore case study into a spatial model using machinelearningmethods. The modelling was done in two steps. First, the processproperties were deployed into a geological database by building nonspatialprocess models. Second, the process properties estimated in thegeological database were extracted together with only their coordinates(x, y, z) and iron grades and spatial process models were built.Modelling methods were evaluated and compared in terms of relativestandard deviation (RSD). The lower RSD for decision tree methodssuggests that those methods may be preferential when modelling non-linearprocess properties.

  • 40.
    Naderi, Arman
    et al.
    Department of Soil Science, University of Zanjan, Zanjan, Iran.
    Delavar, Mohammed Amir
    Department of Soil Science, University of Zanjan, Zanjan, Iran.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Hosseini, Mehdi
    Department of Chemistry, Faculty of Basic Science, Ayatollah Boroujerdi University, Boroujerd, Iran.
    Development of surface reaction of nano-colloid minerals using novel ionic liquids and assessing their removal ability for Pb(II) and Hg(II)2020In: Arabian Journal of Geosciences, ISSN 1866-7511, E-ISSN 1866-7538, Vol. 13, no 10, article id 381Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to produce novel eco-friendly organoclays for removing toxic elements from aqueous environment. In the present research, nano-bentonite (Bent) and nano-montmorillonite (MT) minerals were treated with novel ionic liquids including 1-methyl-3-octylimidazolium chloride ([Omim][Cl]), 3,3′-(hexane-1,6-diyl) bis (1-methyl-imidazolium) bromide chloride ([H(mim)2[Br][Cl]), and 1-hexyl-3-methylimidazolium chloride ([Hmim][Cl]) to produce organoclays with ecofriendly features. The products were investigated using X-ray diffraction (XRD); Fourier transformed infrared spectroscopy (FTIR); carbon, hydrogen, and nitrogen elemental analysis (CHN); scanning electron microscope (SEM); and specific surface area (SSA) (via N2-BET method) techniques. Finally, the mechanism involved in the adsorption of Pb(II) and Hg(II) onto organoclays from the aqueous phase was investigated by applying most three popular experimental adsorption isotherms including Langmuir, Freundlich, and Sips models. The results showed that by intercalating ILs, first XRD diffraction (d001) of the modified clays was increased. Based on the results of Sips model, [H(mim)2]-clays and [Omim]-clays had maximum adsorption capacity and maximum adsorption affinity. To the best of the authors’ knowledge, the amount of removed toxic metals by the modified clays in this research was more than those in the previous researches. This research demonstrated that clay mineral modifications using ILs is enhanced clay d-spacing and facilitated diffusion of the large hazardous metal ions into clay interlayer spaces. These increased their potential for toxic metal immobilization as green adsorbents.

  • 41.
    Nwaila, Glen T.
    et al.
    Wits Mining Institute (WMI), University of the Witwatersrand, Private Bag 3, 2050 Wits, South Africa.
    Frimmel, Hartwig E.
    Bavarian Georesources Centre, Department of Geodynamics and Geomaterials Research, Institute of Geography and Geology, University of Würzburg, Am Hubland, D-97074, Würzburg, Germany; Department of Geological Sciences, University of Cape Town, Rondebosch, 7700, South Africa.
    Zhang, Steven E.
    Wits Mining Institute (WMI), University of the Witwatersrand, Private Bag 3, 2050 Wits, South Africa; Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E9, Canada; SmartMin Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Bourdeau, Julie E.
    Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E9, Canada.
    Tolmay, Leon C.K.
    Tolmay Enterprises, 150 Galena Avenue, Kloofendal, 1703, South Africa.
    Durrheim, Raymond J.
    School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    The minerals industry in the era of digital transition: An energy-efficient and environmentally conscious approach2022In: Resources policy, ISSN 0301-4207, E-ISSN 1873-7641, Vol. 78, article id 102851Article, review/survey (Refereed)
    Abstract [en]

    The concept of the 4th industrial revolution is becoming a strategic determinant of sustainability, success and competitiveness in the modern mining sector. The importance of digital transformation in the mining industry has long been debated, hampered in part by the conservative nature of the mining sector. Much of the debate has focused on choosing suitable mining techniques that provide acceptable levels of ore/waste selectivity, the scale of implementation, cost reduction and suitable metallurgical extraction techniques. The purpose of this review is to give an overview of the digital transformation of the minerals and extractive industry with a focus towards energy efficiency and environmental sustainability. We address: (a) geological elements that influence the level of selectivity during mining, and technologies that deal with waste rejection; (b) eco-friendly techniques, such as tunnel-boring machines, or the use of non-explosive techniques that can assist fragmentation of ores, thereby decreasing energy requirements during mineral processing and improving mineral recovery; (c) use of low-water-consumption automated ore-waste sorting systems; (d) selective metal leaching using coarse particle percolation as an alternate method for treating complicated low-grade ores; and (e) assessing new technological boundaries for the mineral sector. A combination of these aforementioned processes will significantly reduce mining waste. Orebody features, mining methods and equipment, desired scales of implementation, alignment with circular strategies, ore extraction efficiency, and socio-economic factors all play a role in the development and implementation of new technologies and techniques.

  • 42.
    Nwaila, Glen T.
    et al.
    School of Geosciences, University of the Witwatersrand, Wits, South Africa.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Becker, Megan
    Minerals to Metals Initiative, Department of Chemical Engineering, University of Cape Town, Rondebosch, South Africa.
    Frimmel, Hartwig E.
    Bavarian Georesources Centre (BGC), Institute of Geography and Geology, University of Würzburg, Würzburg, Germany. Department of Geological Sciences, University of Cape Town, Rondebosch, South Africa.
    Petersen, Jochen
    Minerals to Metals Initiative, Department of Chemical Engineering, University of Cape Town, Rondebosch, South Africa.
    Zhang, Steven
    School of Geosciences, University of the Witwatersrand, Wits, South Africa.
    Geometallurgical Approach for Implications of Ore Blending on Cyanide Leaching and Adsorption Behavior of Witwatersrand Gold Ores, South Africa2020In: Natural Resources Research, ISSN 1520-7439, E-ISSN 1573-8981, Vol. 29, no 2, p. 1007-1030Article in journal (Refereed)
    Abstract [en]

    Gold production in South Africa is projected to continue its decline in future, and prospects for discovery of new high-grade deposits are limited. Many of the mining companies have resorted to mining and processing low-grade and complex gold ores. Such ores are technically challenging to process, which results in low recovery rates, excessive reagent consumption and high operating costs when compared to free-milling gold ores. In the Witwatersrand mines, options of blending low-grade gold ores with high-grade ores exist. Although it is well known that most of the Witwatersrand gold ores are highly amenable to gold cyanidation, not much is known on the leachability of blended ores, especially the effects of mineralogical and metallurgical variability between different gold ores. In this study, we apply a geometallurgical approach to investigate mineralogical and metallurgical factors that influence the leaching of blended ores in a set of bottle shaker and reactor column tests. Three gold-bearing conglomerate units, so-called reefs, i.e., Carbon Leader Reef, Ventersdorp Contact Reef and the Black Reef, all in the Carletonville goldfield, were sampled. The ores were prepared using a terminator jaw crusher followed by vertical spindle pulverizer (20 kg aliquot) and high-pressure grinding rolls (80 kg aliquot). Mineralogical analysis was conducted using a range of complementary tools such as optical microscopy, QEMSCAN and micro–XCT. The results show that Witwatersrand gold ores are amenable to the process of ore blending. Some of the ores, however, contain impervious inert gangue and reactive ore minerals. Leach solution can only access gold locked in impervious gangue minerals through HPGR-induced pores and/or cracks. The optimum ore blending ratio of the bottle shaker experiments (p80 = − 75 μm) comprises 60% Carbon Leader Reef, 20% Ventersdorp Contact Reef and 20% Black Reef and yields 92% recovered Au over a leach period of 40 h. Blended ores with high carbonaceous material (> 1 wt% carbonaceous material, (Black Reef = 36–60%) yield lower recoveries of 60–69% Au). Ore leaching at the mixed-bed reactor column (− 75 μm and − 5.6/+ 4 mm) yields about 70% over a leach period of two weeks. We therefore suggest that the feasibility of ore blending is strongly controlled by the mineralogy of the constituent ores and that a mixed-bed reactor may be a viable alternative method for leaching of the low-grade Witwatersrand gold ores. Material from certain reefs, such as the Black Reef, has synergistic/antagonistic (nonadditive) blending effects. The overall implication of this study is that ore blending ratios, effects of comminution on mineral liberation, an association of gold with other minerals, and gold adsorption behavior will greatly inform future technology choices in the area of geometallurgy.

  • 43.
    Nwaila, Glen T.
    et al.
    School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Zhang, Steven E.
    PG Techno Wox (Pty) Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Frimmel, Hartwig E.
    Bavarian Georesources Centre (BGC), Institute of Geography and Geology, University of Würzburg, Am Hubland, 97074, Würzburg, Germany; Department of Geological Sciences, University of Cape Town, Rondebosch, 7700, South Africa.
    Tolmay, Leon C.K.
    Tolmay Enterprises, 150 Galena Avenue, Kloofendal, 1703, South Africa.
    Rose, Derek H.
    Department of Geology, University of Johannesburg, Auckland Park, Kingsway Campus, 2006, South Africa.
    Nwaila, Phumzile C.
    PG Techno Wox (Pty) Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Bourdeau, Julie E.
    PG Techno Wox (Pty) Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Valorisation of mine waste - Part I: Characteristics of, and sampling methodology for, consolidated mineralised tailings by using Witwatersrand gold mines (South Africa) as an example2021In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 295, article id 113013Article in journal (Refereed)
    Abstract [en]

    The quest for steady primary supplies of critical raw materials (CRMs) creates significant waste, which is inevitably generated at each phase of mining and mineral processing. Waste from extraction, separation and refinement of non-renewable natural resources is accumulated globally and creates not only environmental hazards but also economic possibilities. Mine waste management is an expensive and prolonged task but unavoidable. Mine tailings, especially historical ones, can contain economically feasible resources, and given the right condition, such tailings could be reutilised through a waste valorisation concept. A prominent example are the Witwatersrand gold mine tailings in South Africa, which have been reused in small-scale projects. Tailing reutilisation is only possible if a sound classification, sampling and resource modelling framework is established to thoroughly and accurately profile the economic, environmental, health and geometallurgical aspects. Our study on valorisation of mine waste is presented in two parts: Here, in Part I, we focus on the essential components of a mine waste valorisation framework that includes the characterization and development of a systematic sampling framework for consolidated mineralised tailings. The development of a mine waste valorisation framework will hopefully enable worldwide reduction and reutilisation of mine waste.

  • 44.
    Nwaila, Glen T.
    et al.
    School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Zhang, Steven E.
    PG Techno Wox (Pty) Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Tolmay, Leon C.K.
    Tolmay Enterprises, 150 Galena Avenue, Kloofendal, 1703, South Africa.
    Rose, Derek H.
    Department of Geology, University of Johannesburg, Auckland Park, Kingsway Campus, 2006, South Africa.
    Nwaila, Phumzile C.
    PG Techno Wox (Pty) Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Bourdeau, Julie E.
    PG Techno Wox (Pty) Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Frimmel, Hartwig E.
    Bavarian Georesources Centre, Dept. of Geodynamics & Geomaterials Research, Institute of Geography and Geology, University of Würzburg, Am Hubland, D, 97074, Würzburg, German; Department of Geological Sciences, University of Cape Town, Rondebosch, 7700, South Africa.
    Valorisation of mine waste - Part II: Resource evaluation for consolidated and mineralised mine waste using the Central African Copperbelt as an example2021In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 299, article id 113553Article in journal (Refereed)
    Abstract [en]

    Mine waste can create long-term and occasionally catastrophic environmental degradation. Due diligence of mine waste in the form of monitoring and maintenance requires a constant supply of societal resources. Furthermore, mine waste is unlikely to disappear with current mining methods and instead, it is more likely to accumulate at a faster rate due to decreasing primary ore grades and increasing societal demands. However, mine waste can be a societal asset, as it can offer an alternative source of partly critical raw materials (CRMs) that can augment primary sources and provide an opportunity to mitigate supply-risk while ensuring sustainability and easing geopolitical tensions. Cobalt is a critical raw material that is largely a by-product of mining of copper, nickel and platinum-group element ores. It is an element that the renewable energy and high-tech sectors critically depend on and for which no reasonable substitutes currently exist. The majority of the global cobalt production stems from the Central African Copperbelt. Published cobalt production figures for the Central African Copperbelt were used to evaluate cobalt tailings from the Central African Copperbelt. As part of a waste valorisation framework that focuses on primarily on the technical aspects of mine waste valorisation, this study assesses the application of key geostatistical methods, such as kriging and conditional simulation, followed by uniform conditioning, to evaluate the resource potential in a hypothetical copper-cobalt tailing deposit from the Central African Copperbelt. The results indicate that methods such as traditional algorithmic kriging, sequential Gaussian simulation and uniform conditioning are highly effective tools in resource modelling of mine waste. The resource assessment framework component developed in this study makes it possible to systematically characterise, profile and model any mine waste storage facility and thus supplements other framework components discussed in an accompanying paper to maximise mine waste utilization.

  • 45.
    Nwaila, Glen T.
    et al.
    Wits Mining Institute (WMI) and School of Geosciences, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg 2000, South Africa.
    Manzi, Musa S.D.
    Wits Mining Institute (WMI) and School of Geosciences, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg 2000, South Africa.
    Zhang, Steven E.
    PG Techno Wox (Pty) Limited, 39 Kiewiet Street, Helikon Park 1759, South Africa; Geological Survey of Canada, 601 Booth Street, Ottawa, ON K1A 0E9, Canada.
    Bourdeau, Julie E.
    Geological Survey of Canada, 601 Booth Street, Ottawa, ON K1A 0E9, Canada.
    Bam, Lunga C.
    Department of Radiation Science, Nuclear Energy Corporation of South African (NECSA), Pretoria 0001, South Africa.
    Rose, Derek H.
    Department of Geology, University of Johannesburg, P.O. Box 524 Auckland Park 2006, Gauteng, South Africa.
    Maselela, Kebone
    Wits Mining Institute (WMI) and School of Geosciences, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg 2000, South Africa.
    Reid, David L.
    Department of Geological Sciences, University of Cape Town, Rondebosch 7700, South Africa.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Durrheim, Raymond J.
    Wits Mining Institute (WMI) and School of Geosciences, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg 2000, South Africa.
    Constraints on the Geometry and Gold Distribution in the Black Reef Formation of South Africa Using 3D Reflection Seismic Data and Micro-X-ray Computed Tomography2022In: Natural Resources Research, ISSN 1520-7439, E-ISSN 1573-8981, Vol. 31, no 3, p. 1225-1244Article in journal (Refereed)
    Abstract [en]

    Geological and geophysical models are essential for developing reliable mine designs and mineral processing flowsheets. For mineral resource assessment, mine planning, and mineral processing, a deeper understanding of the orebody's features, geology, mineralogy, and variability is required. We investigated the gold-bearing Black Reef Formation in the West Rand and Carletonville goldfields of South Africa using approaches that are components of a transitional framework toward fully digitized mining: (1) high-resolution 3D reflection seismic data to model the orebody; (2) petrography to characterize Au and associated ore constituents (e.g., pyrite); and (3) 3D micro-X-ray computed tomography (µCT) and machine learning to determine mineral association and composition. Reflection seismic reveals that the Black Reef Formation is a planar horizon that dips < 10° and has a well-preserved and uneven paleotopography. Several large-scale faults and dikes (most dipping between 65° and 90°) crosscut the Black Reef Formation. Petrography reveals that gold is commonly associated with pyrite, implying that µCT can be used to assess gold grades using pyrite as a proxy. Moreover, we demonstrate that machine learning can be used to discriminate between pyrite and gold based on physical characteristics. The approaches in this study are intended to supplement rather than replace traditional methodologies. In this study, we demonstrated that they permit novel integration of micro-scale observations into macro-scale modeling, thus permitting better orebody assessment for exploration, resource estimation, mining, and metallurgical purposes. We envision that such integrated approaches will become a key component of future geometallurgical frameworks.

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  • 46.
    Nwaila, Glen T.
    et al.
    Wits Mining Institute, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg, 2000, South Africa.
    Zhang, Steven E.
    Wits Mining Institute, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg, 2000, South Africa; Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E8, Canada.
    Bourdeau, Julie E.
    Wits Mining Institute, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg, 2000, South Africa; Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E8, Canada.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Carranza, Emmanuel John M.
    Department of Geology, University of the Free State, 205 Nelson Mandela Dr, Bloemfontein, 9301, South Africa.
    Artificial intelligence-based anomaly detection of the Assen iron deposit in South Africa using remote sensing data from the Landsat-8 Operational Land Imager2022In: Artificial Intelligence in Geosciences, E-ISSN 2666-5441, Vol. 3, p. 71-85Article in journal (Refereed)
    Abstract [en]

    Most known mineral deposits were discovered by accident using expensive, time-consuming, and knowledge-based methods such as stream sediment geochemical data, diamond drilling, reconnaissance geochemical and geophysical surveys, and/or remote sensing. Recent years have seen a decrease in the number of newly discovered mineral deposits and a rise in demand for critical raw materials, prompting exploration geologists to seek more efficient and inventive ways for processing various data types at different phases of mineral exploration. Remote sensing is one of the most sought-after tools for early-phase mineral prospecting because of its broad coverage and low cost. Remote sensing images from satellites are publicly available and can be utilised for lithological mapping and mineral exploitation. In this study, we extend an artificial intelligence-based, unsupervised anomaly detection method to identify iron deposit occurrence using Landsat-8 Operational Land Imager (OLI) satellite imagery and machine learning. The novelty in our method includes: (1) knowledge-guided and unsupervised anomaly detection that does not assume any specific anomaly signatures; (2) detection of anomalies occurs only in the variable domain; and (3) a choice of a range of machine learning algorithms to balance between explain-ability and performance. Our new unsupervised method detects anomalies through three successive stages, namely (a) stage I – acquisition of satellite imagery, data processing and selection of bands, (b) stage II – predictive modelling and anomaly detection, and (c) stage III – construction of anomaly maps and analysis. In this study, the new method was tested over the Assen iron deposit in the Transvaal Supergroup (South Africa). It detected both the known areas of the Assen iron deposit and additional deposit occurrence features around the Assen iron mine that were not known. To summarise the anomalies in the area, principal component analysis was used on the reconstruction errors across all modelled bands. Our method enhanced the Assen deposit as an anomaly and attenuated the background, including anthropogenic structural anomalies, which resulted in substantially improved visual contrast and delineation of the iron deposit relative to the background. The results demonstrate the robustness of the proposed unsupervised anomaly detection method, and it could be useful for the delineation of mineral exploration targets. In particular, the method will be useful in areas where no data labels exist regarding the existence or specific spectral signatures of anomalies, such as mineral deposits under greenfield exploration.

  • 47.
    Nwaila, Glen T.
    et al.
    Wits Mining Institute, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg 2000, South Africa; School of Geosciences, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg 2000, South Africa.
    Zhang, Steven E.
    Wits Mining Institute, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg 2000, South Africa; PG Techno Wox (Pty) Limited, 39 Kiewiet Street, Randfontein, 1759, South Africa; Geological Survey of Canada, 601 Booth Street, Ottawa, ON, K1A 0E9, Canada.
    Bourdeau, Julie E.
    Wits Mining Institute, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg, 2000, South Africa; Geological Survey of Canada, 601 Booth Street, Ottawa, ON, K1A 0E9, Canada.
    Negwangwatini, Elekanyani
    School of Geosciences, University of the Witwatersrand, 1 Jan Smuts Ave., Johannesburg, 2000, South Africa.
    Rose, Derek H.
    Department of Geology, University of Johannesburg, P.O. Box 524, Johannesburg, 2006, South Africa.
    Burnett, Mark
    AMC Consultants, Level 7, Nicholsons House Nicholsons Walk, Maidenhead, SL6 1LD, UK.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Data-Driven Predictive Modeling of Lithofacies and Fe In-Situ Grade in the Assen Fe Ore Deposit of the Transvaal Supergroup (South Africa) and Implications on the Genesis of Banded Iron Formations2022In: Natural Resources Research, ISSN 1520-7439, E-ISSN 1573-8981, Vol. 31, no 5, p. 2369-2395Article in journal (Refereed)
    Abstract [en]

    The Assen Fe ore deposit is a banded iron formation (BIF)-hosted orebody, occurring in the Penge Formation of the Transvaal Supergroup, located 50 km northwest of Pretoria in South Africa. Most BIF-hosted Fe ore deposits have experienced post-depositional alteration including supergene enrichment of Fe and low-grade regional metamorphism. Unlike most of the known BIF-hosted Fe ore deposits, high-grade hematite (> 60% Fe) in the Assen Fe ore deposit is located along the lithological contacts with dolerite intrusions. Due to the variability in alteration levels, identifying the lithologies present within the various parts of the Assen Fe ore deposit, specifically within the weathering zone, is often challenging. To address this challenge, machine learning was applied to enable the automatic classification of rock types identified within the Assen Fe ore mine and to predict the in-situ Fe grade. This classification is based on geochemical analyses, as well as petrography and geological mapping. A total of 21 diamond core drill cores were sampled at 1 m intervals, covering all the lithofacies present at Assen mine. These were analyzed for major elements and oxides by means of X-ray fluorescence spectrometry. Numerous machine learning algorithms were trained, tested and cross-validated for automated lithofacies classification and prediction of in-situ Fe grade, namely (a) k-nearest neighbors, (b) elastic-net, (c) support vector machines (SVMs), (d) adaptive boosting, (e) random forest, (f) logistic regression, (g) Naive Bayes, (h) artificial neural network (ANN) and (i) Gaussian process algorithms. Random forest, SVM and ANN classifiers yield high classification accuracy scores during model training, testing and cross-validation. For in-situ Fe grade prediction, the same algorithms also consistently yielded the best results. The predictability of in-situ Fe grade on a per-lithology basis, combined with the fact that CaO and SiO2 were the strongest predictors of Fe concentration, support the hypothesis that the process that led to Fe enrichment in the Assen Fe ore deposit is dominated by supergene processes. Moreover, we show that predictive modeling can be used to demonstrate that in this case, the main differentiator between the predictability of Fe concentration between different lithofacies lies in the strength of multivariate elemental associations between Fe and other oxides. Localized high-grade Fe ore along with lithological contacts with dolerite intrusion is indicative of intra-basinal fluid circulation from an already Fe-enriched hematite. These findings have a wider implication on lithofacies classification in weathered rocks and mobility of economic valuable elements such as Fe.

  • 48.
    Patel, Alok
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Enman, Josefine
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Gulkova, Anna
    Boliden Mineral AB, SE- 936 32 Boliden, Sweden.
    Guntoro, Pratama Istiadi
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Dutkiewicz, Agata
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Rova, Ulrika
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Christakopoulos, Paul
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Matsakas, Leonidas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Integrating biometallurgical recovery of metals with biogenic synthesis of nanoparticles2021In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 263, article id 128306Article in journal (Refereed)
    Abstract [en]

    Industrial activities, such as mining, electroplating, cement production, and metallurgical operations, as well as manufacturing of plastics, fertilizers, pesticides, batteries, dyes or anticorrosive agents, can cause metal contamination in the surrounding environment. This is an acute problem due to the non-biodegradable nature of metal pollutants, their transformation into toxic and carcinogenic compounds, and bioaccumulation through the food chain. At the same time, platinum group metals and rare earth elements are of strong economic interest and their recovery is incentivized. Microbial interaction with metals or metals-bearing minerals can facilitate metals recovery. Metal nanoparticles are gaining increasing attention due to their unique characteristics and application as antimicrobial and antibiofilm agents, biocatalysts, in targeted drug delivery, for wastewater treatment, and in water electrolysis. Ideally, metal nanoparticles should be homogenous in shape and size, and not toxic to humans or the environment. Microbial synthesis of nanoparticles represents a safe, and environmentally friendly, alternative to chemical and physical methods. In this review article, we mainly focus on metal and metal salts nanoparticles synthesized by various microorganisms, such as bacteria, fungi, microalgae, and yeasts, as well as their advantages in biomedical, health, and environmental applications.

  • 49.
    Rachidi, Ntebatše R.
    et al.
    School of Geosciences, University of the Witwatersrand, Private Bag 3 Wits 2050, South Africa.
    Nwaila, Glen T.
    School of Geosciences, University of the Witwatersrand, Private Bag 3 Wits 2050, South Africa.
    Zhang, Steven E.
    SmartMin Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Bourdeau, Julie E.
    SmartMin Limited, 39 Kiewiet Street, Helikon Park, 1759, South Africa.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Assessing cobalt supply sustainability through production forecasting and implications for green energy policies2021In: Resources policy, ISSN 0301-4207, E-ISSN 1873-7641, Vol. 74, article id 102423Article in journal (Refereed)
    Abstract [en]

    Transitioning to a decarbonized and circular economy is paramount for climate change mitigation and sustainable development. In this paper we assess the global production trends of cobalt, an energy-transition metal (ETM), and its supply sustainability. Accurate production forecasting of ETMs is essential to understand the dynamics of energy supply security and adequately plan for a change from fossil fuel energy to renewable energy production. Evaluations of market concentrations demonstrate that cobalt is a high-risk market characterized by production fluctuations and supply-chain complexities. We forecast the cobalt production using several methods. Results from both of the Auto Regressive Integrated Moving Average (ARIMA) and Holt's methods show a linear increase in world cobalt production for the short term, while a Hubbert model predicts a world production decline beginning in the late 2010s. These predictions, coupled with geopolitical, socio-environmental, and techno-economic influences on the market, reinforce the concern regarding cobalt supply sustainability. Although alternative avenues for sourcing cobalt, such as secondary urban mining and stockpiling exist, they are unlikely to become major suppliers in the short term, which highlights the need to accurately forecast primary production. Increasing interests in critical raw materials (CRMs) in policy spheres also heightens the necessity to anticipate the future of cobalt supply as governmental entities acknowledge the imbalance of CRMs in international trade. Well-researched and well-designed policies, that incorporate environmental sustainability and non-discriminatory economic growth, can facilitate an equitable shift to a greener and more circular economy. At the forefront of this shift should be ethical environmental and resource governance that recognizes the inequalities in socio-economic development and energy-transition, and mandates for a just transition towards a low carbon future.

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  • 50.
    Rincon, Jonathan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Jansson, Nils
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Thomas, Helen
    Boliden, Exploration department, Boliden, Sweden.
    Kaiser, Majka Christiane
    Boliden, Exploration department, Boliden, Sweden.
    Persson, Mac Fjellerad
    Boliden, Exploration department, Boliden, Sweden.
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Wanhainen, Christina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Spatial and temporal controls of minor and trace elements in remobilised sulphides of the metamorphosed Rävliden North VHMS deposit, Skellefte district, SwedenManuscript (preprint) (Other academic)
12 1 - 50 of 64
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