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Bahrami, A., Ghorbani, Y., Sharif, J. A., Kazemi, F., Abdollahi, M., Salahshur, A. & Danesh, A. (2019). A geometallurgical study of flotation performance in supergene and hypogene zones of Sungun copper deposit. Mineral Processing and Extractive Metallurgy
Open this publication in new window or tab >>A geometallurgical study of flotation performance in supergene and hypogene zones of Sungun copper deposit
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2019 (English)In: Mineral Processing and Extractive Metallurgy, ISSN 2572-6641Article in journal (Refereed) Epub ahead of print
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.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Sulfide minerals, oxide minerals, supergene, hypogene, recovery, flotation rate
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-73223 (URN)10.1080/25726641.2019.1591794 (DOI)
Available from: 2019-03-18 Created: 2019-03-18 Last updated: 2019-03-18
Bahrami, A., Ghorbani, Y., Hosseini, M. R., Kazemi, F., Abdollahi, M. & Danesh, A. (2019). Combined Effect of Operating Parameters on Separation Efficiency and Kinetics of Copper Flotation. Mining, metallurgy & exploration, 36(2), 409-421
Open this publication in new window or tab >>Combined Effect of Operating Parameters on Separation Efficiency and Kinetics of Copper Flotation
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2019 (English)In: Mining, metallurgy & exploration, ISSN 2524-3462, Vol. 36, no 2, p. 409-421Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Taguchi, Flotation, Collector, Kinetics, Copper, Sungun copper complex
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-71161 (URN)10.1007/s42461-018-0005-y (DOI)000474227100016 ()
Note

Validerad;2019;Nivå 2;2019-08-16 (johcin)

Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2019-08-16Bibliographically approved
Lishchuk, V., Lund, C. & Ghorbani, Y. (2019). Evaluation and comparison of different machine-learning methods to integrate sparse process data into a spatial model in geometallurgy. Minerals Engineering, 134, 156-165
Open this publication in new window or tab >>Evaluation and comparison of different machine-learning methods to integrate sparse process data into a spatial model in geometallurgy
2019 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 134, p. 156-165Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Data Integration, Spatial Model, WLIMS, Davis Tube, Iron Ore, Machine-learning, Geometallurgy.
National Category
Mineral and Mine Engineering Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-71579 (URN)10.1016/j.mineng.2019.01.032 (DOI)000462107200015 ()2-s2.0-85060907032 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-02-11 (svasva)

Available from: 2018-11-14 Created: 2018-11-14 Last updated: 2019-04-11Bibliographically approved
Nwaila, G. T., Ghorbani, Y., Becker, M., Frimmel, H. E., Petersen, J. & Zhang, S. (2019). Geometallurgical Approach for Implications of Ore Blending on Cyanide Leaching and Adsorption Behavior of Witwatersrand Gold Ores, South Africa. Natural Resources Research
Open this publication in new window or tab >>Geometallurgical Approach for Implications of Ore Blending on Cyanide Leaching and Adsorption Behavior of Witwatersrand Gold Ores, South Africa
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2019 (English)In: Natural Resources Research, ISSN 1520-7439, E-ISSN 1573-8981Article in journal (Refereed) Epub ahead of print
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.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Gold, Geometallurgy, Cyanide leaching, Ore blending, Process mineralogy, Witwatersrand gold ores
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-75498 (URN)10.1007/s11053-019-09522-4 (DOI)
Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2019-08-13
Bahrami, A., Mirmohammadi, M., Ghorbani, Y., Kazemi, F., Abdollahi, M. & Danesh, A. (2019). Process mineralogy as a key factor affecting the flotation kinetics of copper sulfide minerals. International Journal of Minerals, Metallurgy and Materials, 26(4), 430-439
Open this publication in new window or tab >>Process mineralogy as a key factor affecting the flotation kinetics of copper sulfide minerals
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2019 (English)In: International Journal of Minerals, Metallurgy and Materials, ISSN 1674-4799, E-ISSN 1869-103X, Vol. 26, no 4, p. 430-439Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
microscopic analysis, flotation, kinetics, second order rectangular distribution model, sulphide minerals
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-73642 (URN)10.1007/s12613-019-1733-9 (DOI)000464703200004 ()
Note

Validerad;2019;Nivå 2;2019-04-15 (svasva)

Available from: 2019-04-15 Created: 2019-04-15 Last updated: 2019-05-02Bibliographically approved
Bahrami, A., Kazemi, F. & Ghorbani, Y. (2019). The Order of Kinetic Models, Rate Constant Distribution, and Maximum Combustible Recovery in Gilsonite Flotation. Mining, Metallurgy & Exploration
Open this publication in new window or tab >>The Order of Kinetic Models, Rate Constant Distribution, and Maximum Combustible Recovery in Gilsonite Flotation
2019 (English)In: Mining, Metallurgy & Exploration, ISSN 2524-3462Article in journal (Refereed) Epub ahead of print
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.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Flotation, Kinetic models, Gilsonite Bitumen, Asphaltum, Iran
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-75022 (URN)10.1007/s42461-019-0079-1 (DOI)
Available from: 2019-06-26 Created: 2019-06-26 Last updated: 2019-06-26
Guntoro, P. I., Ghorbani, Y. & Rosenkranz, J. (2019). Use of X-ray Micro-computed Tomography (µCT) for 3-D Ore Characterization: A Turning Point in Process Mineralogy. In: : . Paper presented at 26th International Mining Congress and Exhibition (IMCET 2019), Antalya, April 16-19, 2019 (pp. 1044-1054).
Open this publication in new window or tab >>Use of X-ray Micro-computed Tomography (µCT) for 3-D Ore Characterization: A Turning Point in Process Mineralogy
2019 (English)Conference paper, Published 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.

Keywords
X-ray micro-tomography (µCT), process mineralogy, ore characterization
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-73716 (URN)
Conference
26th International Mining Congress and Exhibition (IMCET 2019), Antalya, April 16-19, 2019
Funder
EU, Horizon 2020
Available from: 2019-04-23 Created: 2019-04-23 Last updated: 2019-04-25Bibliographically approved
Guntoro, P. I., Ghorbani, Y., Koch, P.-H. & Rosenkranz, J. (2019). X-ray Microcomputed Tomography (µCT) for Mineral Characterization: A Review of Data Analysis Methods. Minerals, 9(3), Article ID 183.
Open this publication in new window or tab >>X-ray Microcomputed Tomography (µCT) for Mineral Characterization: A Review of Data Analysis Methods
2019 (English)In: Minerals, ISSN 2075-163X, E-ISSN 2075-163X, Vol. 9, no 3, article id 183Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Basel, Switzerland: MDPI, 2019
Keywords
X-ray microcomputed tomography, data analysis, mineral characterization, texture, mineralogy
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-73224 (URN)10.3390/min9030183 (DOI)000464421700002 ()2-s2.0-85064225739 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-03-18 (svasva)

Available from: 2019-03-18 Created: 2019-03-18 Last updated: 2019-04-30Bibliographically approved
Leiva, C. A., Arcos, K. V., Poblete, D. A., Serey, E. A., Torres, C. M. & Ghorbani, Y. (2018). Design and Evaluation of an Expert System in a Crushing Plant. Minerals, 8(10), Article ID 469.
Open this publication in new window or tab >>Design and Evaluation of an Expert System in a Crushing Plant
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2018 (English)In: Minerals, ISSN 2075-163X, E-ISSN 2075-163X, Vol. 8, no 10, article id 469Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
MDPI, 2018
Keywords
improvement, expert system, knowledge-based system, milling, crushing
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-71397 (URN)10.3390/min8100469 (DOI)2-s2.0-85056347044 (Scopus ID)
Note

Validerad;2018;Nivå 2; 2018-11-06 (inah)

Available from: 2018-10-31 Created: 2018-10-31 Last updated: 2018-11-21Bibliographically approved
Ilankoon, I., Ghorbani, Y., Nan Chong, M., Herath, G., Moyo, T. & Petersen, J. (2018). E-waste in the international context: A review of trade flows, regulations, hazards, waste management strategies and technologies for value recovery. Waste Management, 82, 258-275
Open this publication in new window or tab >>E-waste in the international context: A review of trade flows, regulations, hazards, waste management strategies and technologies for value recovery
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2018 (English)In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 82, p. 258-275Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Environmental pollution, E-waste recycling, Hydrometallurgy, Pyrometallurgy, Trans-boundary movement of e-waste, Waste management
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-71375 (URN)10.1016/j.wasman.2018.10.018 (DOI)000454467900027 ()30509588 (PubMedID)2-s2.0-85055580206 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-10-30 (johcin) 

Available from: 2018-10-30 Created: 2018-10-30 Last updated: 2019-03-27Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-5228-3888

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