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Publications (10 of 14) Show all publications
Chelgani, S. C., Parian, M., Semsari, P., Ghorbani, Y. & Rosenkranz, J. (2019). A comparative study on the effects of dry and wet grinding on mineral flotation separation: a review. Journal of Materials Research and Technology
Open this publication in new window or tab >>A comparative study on the effects of dry and wet grinding on mineral flotation separation: a review
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2019 (English)In: Journal of Materials Research and Technology, ISSN 2238-7854Article in journal (Refereed) Epub ahead of print
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.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Flotation, Energy consumption, Grinding media type, HPGR, Dry grinding, Wet grinding
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-75591 (URN)10.1016/j.jmrt.2019.07.053 (DOI)
Available from: 2019-08-20 Created: 2019-08-20 Last updated: 2019-08-25
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
Guntoro, P. I., Tiu, G., Ghorbani, Y., Lund, C. & Rosenkranz, J. (2019). Application of machine learning techniques in mineral phase segmentation for X-ray microcomputed tomography (µCT) data. Minerals Engineering, 142, Article ID 105882.
Open this publication in new window or tab >>Application of machine learning techniques in mineral phase segmentation for X-ray microcomputed tomography (µCT) data
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2019 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 142, article id 105882Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
X-ray micro-tomography (µCT), Machine learning, Mineral segmentation, Feature-based classification, Feature matching
National Category
Metallurgy and Metallic Materials Geology
Research subject
Mineral Processing; Ore Geology
Identifiers
urn:nbn:se:ltu:diva-75703 (URN)10.1016/j.mineng.2019.105882 (DOI)2-s2.0-85070948239 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-08-27 (svasva)

Available from: 2019-08-27 Created: 2019-08-27 Last updated: 2019-09-03Bibliographically approved
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
Bahrami, A., Kazemi, F. & Ghorbani, Y. (2019). Effect of different reagent regime on the kinetic model and recovery in gilsonite flotation. Journal of Materials Research and Technology
Open this publication in new window or tab >>Effect of different reagent regime on the kinetic model and recovery in gilsonite flotation
2019 (English)In: Journal of Materials Research and Technology, ISSN 2238-7854Article in journal (Refereed) Epub ahead of print
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∞" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 16.2px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">R∞) and particle size was also studied. The results showed that the R∞" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 16.2px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">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.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Flotation, Kinetic models, Gilsonite, Particle size, Reagents
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-75593 (URN)10.1016/j.jmrt.2019.07.063 (DOI)
Available from: 2019-08-20 Created: 2019-08-20 Last updated: 2019-08-20
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
Tiu, G., Jansson, N., Wanhainen, C. & Ghorbani, Y. (2019). Sulfide chemistry and trace element deportment at the metamorphosed Lappberget Zn-Pb-Ag-(Cu-Au) ore body, Sweden: Implications for Mineral Processing. In: Life with Ore Deposits on Earth: Proceedings of the 15th SGA Biennial Meeting 2019. Paper presented at 15th SGA Biennial Meeting, 27-30 August 2019, Glasgow, Scotland (pp. 1486-1489). Glasgow, Scotland, 4
Open this publication in new window or tab >>Sulfide chemistry and trace element deportment at the metamorphosed Lappberget Zn-Pb-Ag-(Cu-Au) ore body, Sweden: Implications for Mineral Processing
2019 (English)In: Life with Ore Deposits on Earth: Proceedings of the 15th SGA Biennial Meeting 2019, Glasgow, Scotland, 2019, Vol. 4, p. 1486-1489Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

The 58 Mt Lappberget Zn-Pb-Ag-(Cu-Au) ore body represents one of the largest and most significant polymetallic base metal sulfide deposits in Sweden. The complex mineralogical characteristics of the ore body pose particularly tough challenges for successful production forecast because of the mixed Zn-Pb-Cu base metals, the complex association of the beneficial Ag and Au, and the presence of influential elements such as Sb, Mn and Mg. Thus, a detailed mineralogical characterization study was conducted, focusing on the deportment of trace and minor elements (including credit and penalty elements). Mineral chemistry data derived from electron microprobe and   laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses reveal the complexity in the composition and associations of the ore minerals, consisting of textural and chemical varieties of sphalerite, galena, chalcopyrite, iron sulfides, antimonides and sulfosalts. Recrystallization, re-mobilization and re-concentration of sulfide minerals, compositional banding, and ductile and brittle deformation textures (i.e. deformation twins on sphalerite, brecciation, bent cleavage planes, etc.) are observed throughout the deposit. The mineralogical and textural complexity and heterogeneity of the sulfide ore are reflected in the variability in grades and recovery from the processing plant.

Place, publisher, year, edition, pages
Glasgow, Scotland: , 2019
Keywords
LA-ICPMS, electron microprobe, Garpenberg, mineral deportment
National Category
Geology
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-75960 (URN)
Conference
15th SGA Biennial Meeting, 27-30 August 2019, Glasgow, Scotland
Projects
MetalIntelligence Project
Funder
EU, Horizon 2020, 722677
Available from: 2019-09-11 Created: 2019-09-11 Last updated: 2019-09-20Bibliographically 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
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-5228-3888

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