Advances in Mineral Processing and Hydrometallurgy—2nd Edition

A special issue of Metals (ISSN 2075-4701). This special issue belongs to the section "Extractive Metallurgy".

Deadline for manuscript submissions: closed (30 September 2024) | Viewed by 20246

Special Issue Editors


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Guest Editor
Kroll Institute for Extractive Metallurgy, Mining Engineering Department & George S. Ansell Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO 80401, USA
Interests: extractive metallurgy; mineral processing; waste minimization; recycling
Special Issues, Collections and Topics in MDPI journals
Nevada Gold Mines, Elko, NV, USA
Interests: extractive metallurgy; mineral processing; waste minimization and recycling
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Please consider submitting some of your excellent work in a Special Issue of Metals devoted to aspects of mineral processing and hydrometallurgy. This also includes characterization along with recycling and waste minimization. Possible topics include mineralogy, geometallurgy, thermodynamics, kinetics, comminution, classification, physical separations, liquid solid separations, leaching, solvent extraction, ion exchange, activated carbon, precipitation, reduction, process economics, and process control. Suggested application areas are in gold, silver, PGMs, aluminum, copper, zinc, lead, nickel, and titanium. Critical metals articles on topics such as lithium, antimony tellurium, gallium, germanium, cobalt, graphite, indium, and the Rare Earths are also welcomed. Both primary and recycled aspects will be considered. Thank you.

Prof. Dr. Corby G. Anderson
Dr. Hao Cui
Guest Editors

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Keywords

  • characterization
  • economics
  • comminution
  • classification
  • separations
  • recycling
  • leaching
  • concentration
  • precipitation
  • reduction
  • waste minimization

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Related Special Issue

Published Papers (10 papers)

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Research

18 pages, 4417 KiB  
Article
Obtention of Suitable Pregnant Leach Solution (PLS) for Copper Solvent Extraction Plants from Copper Concentrate Using Hydrogen Peroxide and Iodine in a Sulfuric Acid–Chloride Medium
by María E. Taboada, Nathalie E. Jamett, German A. Moraga, Pia C. Hernández and Teófilo A. Graber
Metals 2024, 14(7), 817; https://doi.org/10.3390/met14070817 - 16 Jul 2024
Cited by 1 | Viewed by 1465
Abstract
Copper leaching presents an environmentally friendly alternative to traditional sulfide ore processing methods. This study investigates an efficient leaching process for copper concentrate, utilizing a solution of sulfuric acid (H2SO4) and potassium iodide (KI) in a chloride medium (NaCl), [...] Read more.
Copper leaching presents an environmentally friendly alternative to traditional sulfide ore processing methods. This study investigates an efficient leaching process for copper concentrate, utilizing a solution of sulfuric acid (H2SO4) and potassium iodide (KI) in a chloride medium (NaCl), enhanced by hydrogen peroxide (H2O2) at room temperature. A significant aspect of this research was optimizing the KI concentration to minimize iodide sublimation into iodine gas (I2). Through the experimental design, the optimal dosages of reagents were determined, leading to maximized copper extraction of approximately 27% in 45 min of testing at room temperature. The results showed that it is possible to obtain a suitable pregnant leach solution (PLS) (i.e., in the range of 3 to 8 g/L of Cu) for treatment in available copper solvent extraction (SX) plants with a cost of less than 4.5 USD/t Cu, according to the economic analysis carried out. The results of this study determine the most effective operational conditions for leaching and ensure a suitable PLS for SX plants in a cost-effective and environmentally friendly manner. This approach could significantly contribute to more sustainable practices in the mining and processing of copper ores. Full article
(This article belongs to the Special Issue Advances in Mineral Processing and Hydrometallurgy—2nd Edition)
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11 pages, 2477 KiB  
Article
Effect of Incorporation of Sulfation in Columnar Modeling of Oxidized Copper Minerals on Predictions of Leaching Kinetics
by Elena Bruce, Rossana Sepúlveda, Jonathan Castillo and Manuel Saldana
Metals 2024, 14(6), 708; https://doi.org/10.3390/met14060708 - 14 Jun 2024
Viewed by 891
Abstract
Mathematical modeling of columnar leaching is a useful tool for predicting and evaluating the kinetics of copper extraction. One commonly used model for this process is the shrinking core model (SCM). In this study, the aim was to develop a model for column [...] Read more.
Mathematical modeling of columnar leaching is a useful tool for predicting and evaluating the kinetics of copper extraction. One commonly used model for this process is the shrinking core model (SCM). In this study, the aim was to develop a model for column leaching of oxidized copper ore based on the SCM, which incorporates the ore sulfation stage before leaching. In sulfation and leaching laboratory-scale tests, we studied the effect of acid dosage (at 22.8, 34.2, and 45.6 kg/t), humidity (at 90%, 100%, and 110% of the saturation humidity of the mineral), ore granulometry (−3/4″ and −3/8″), and rest time (at 24, 48, 72, and 96 h) on sulfation. We found that the highest sulfation reached 49.7% for both granulometries in studies. In the column tests, the effects of acid dosage (at 34.2, 45.6 kg/t), ore granulometry (−3/4″, −3/8″), and rest time (at 24, 48 h) were studied. When the SCM was applied to these tests, we obtained fit qualities within 63.4% and 74.9%. By incorporating the sulfation factor into the SCM predictions, we observed an average increase in adjustment between 24% and 28%. This method is effective for minerals and operating conditions different from the ones studied. Full article
(This article belongs to the Special Issue Advances in Mineral Processing and Hydrometallurgy—2nd Edition)
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12 pages, 4092 KiB  
Article
Purification of Copper Concentrate from Arsenic under Autoclave Conditions
by Kirill Karimov, Oleg Dizer, Maksim Tretiak and Denis Rogozhnikov
Metals 2024, 14(2), 150; https://doi.org/10.3390/met14020150 - 25 Jan 2024
Viewed by 1435
Abstract
This study presents the results of a two-stage autoclave processing of a copper–arsenic concentrate. Copper concentrate is an important raw material to produce copper and other metals. However, in some cases, the concentrate may contain increased amounts of arsenic, which makes further processing [...] Read more.
This study presents the results of a two-stage autoclave processing of a copper–arsenic concentrate. Copper concentrate is an important raw material to produce copper and other metals. However, in some cases, the concentrate may contain increased amounts of arsenic, which makes further processing difficult. Therefore, the development of modern hydrometallurgical methods for processing copper concentrate with a high arsenic content is an urgent task, which could lead to the optimization of the raw material processing process and the improvement of the quality of the concentrate. It has been established that the optimal conditions for the sequential two-stage autoclave processing of copper–arsenic concentrate are: t = 220–225 °C, τoxidation = 20 min, τtot = 90 min, Po2 = 0.4 MPa, and L:S = 10:1, [H2SO4]initial = 40 g/dm3; in this case, 85% of zinc, 44% of iron, and 78% of arsenic, respectively, are extracted into the solution during both stages and the loss of copper was about 0.01%. This is explained by the fact that at the first stage (oxidation) of the autoclave processing of the copper–arsenic concentrate, copper, together with iron, leaches into the solution, and at the second stage (reduction), copper precipitates out of the solution in the form of chalcocite. Copper in the residue after autoclave leaching is in the form of Cu2S, iron is in the form of pyrite (FeS2), and lead is in the form of anglesite (PbSO4), respectively. The obtained micrographs and EDX mappings clearly show no iron arsenates. This confirms that at the oxidative stage of the developed process, arsenic, removed by 78%, remains in the solution. The remaining arsenic is associated with tennantite, indicating the effectiveness of the treatment process in removing arsenic from the copper–arsenic concentrate. A second important observation is the presence of pronounced areas of copper sulfides in the microphotos without iron and arsenic impurities. This confirms that copper is deposited as chalcocite during the reduction phase of the process, which is the desired result. Full article
(This article belongs to the Special Issue Advances in Mineral Processing and Hydrometallurgy—2nd Edition)
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18 pages, 2520 KiB  
Article
Towards Using MMO Anodes in Zinc Electrorefining: Mn Removal by Simulated Plant Off-Gas
by Masoomeh Askarian, Fariba Mousavi, Roozbeh Mollaabbasi, Elyse Benguerel, Carl Brown, Georges Houlachi and Houshang Alamdari
Metals 2023, 13(10), 1675; https://doi.org/10.3390/met13101675 - 30 Sep 2023
Cited by 1 | Viewed by 1249
Abstract
Implementing mixed metal oxide (MMO) anodes in zinc electrowinning is highly desired due to the considerable reduction in electrical energy consumption. However, the presence of manganese in the electrolyte is a major obstacle for implementing MMO anodes in the zinc cell houses. In [...] Read more.
Implementing mixed metal oxide (MMO) anodes in zinc electrowinning is highly desired due to the considerable reduction in electrical energy consumption. However, the presence of manganese in the electrolyte is a major obstacle for implementing MMO anodes in the zinc cell houses. In this work, we explore the possibility of using plant off-gas, containing SO2, to remove manganese. A SO2/air gas mixture with different SO2 and O2 concentrations was therefore used for the oxidative precipitation of manganese. It was shown that the manganese oxidation reaction is highly pH-dependent. Calcium hydroxide was used to control the pH during the process. Different operating parameters, i.e., pH, SO2/air ratio, reaction time, and effect of cobalt as a reaction catalyst, were investigated. Optimal conditions for manganese removal were reported. Under the optimal conditions, the manganese concentration decreased from 1 g L−1 to less than 1 mg L−1 within 30 min. Precipitates were characterized using EDS, XRF, and XPS techniques and showed coprecipitation of manganese, zinc, gypsum, and cobalt. Full article
(This article belongs to the Special Issue Advances in Mineral Processing and Hydrometallurgy—2nd Edition)
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13 pages, 2789 KiB  
Article
Adsorption of Gold from Copper–Tartrate–ThiosulfateSolutions with Ion-Exchange Resins
by Yan Fu, Junnan Chen, Feng Xie, Zhichao Cao and Wei Wang
Metals 2023, 13(8), 1443; https://doi.org/10.3390/met13081443 - 11 Aug 2023
Viewed by 1047
Abstract
The adsorption behavior of gold from copper–tartrate–thiosulfate solutions with ion-exchange resins was studied in this paper. Experimental parameters include resin dosage, pH, temperature, copper, tartrate, and thiosulfate concentration. A moderate increase in resin dosage, pH, temperature, and tartrate concentration is beneficial for gold [...] Read more.
The adsorption behavior of gold from copper–tartrate–thiosulfate solutions with ion-exchange resins was studied in this paper. Experimental parameters include resin dosage, pH, temperature, copper, tartrate, and thiosulfate concentration. A moderate increase in resin dosage, pH, temperature, and tartrate concentration is beneficial for gold adsorption, but an excessive tartrate concentration or higher temperature depresses the adsorption process. Increasing copper and thiosulfate concentrations may competitively occupy the active sites on the resin surface, leading to a reduction in the gold adsorption capacity. The XPS and FT-IR analyses indicate that copper and gold on the resin after adsorption mainly exist in the form of Cu+ and Au+, and sulfur mainly exists in the form of SO42− and S2O32−. This implies that the use of resin for gold recovery from thiosulfate leachate may face critical challenges because there is inevitably a higher content of copper and thiosulfate. Full article
(This article belongs to the Special Issue Advances in Mineral Processing and Hydrometallurgy—2nd Edition)
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14 pages, 6578 KiB  
Article
Effects of Ammonium Salts on Rare Earth Leaching Process of Weathered Crust Elution-Deposited Rare Earth Ores
by Zhenyue Zhang, Changyu Zhou, Wendou Chen, Fei Long, Zhuo Chen and Ru’an Chi
Metals 2023, 13(6), 1112; https://doi.org/10.3390/met13061112 - 13 Jun 2023
Cited by 6 | Viewed by 2439
Abstract
In order to reveal the influence of ammonium salts on the rare earth leaching process of weathered crust elution-deposited rare earth ores, ammonium acetate, ammonium chloride, and ammonium sulfate were used as leaching agents. The effects of the leaching agent on the rare [...] Read more.
In order to reveal the influence of ammonium salts on the rare earth leaching process of weathered crust elution-deposited rare earth ores, ammonium acetate, ammonium chloride, and ammonium sulfate were used as leaching agents. The effects of the leaching agent on the rare earth leaching efficiency and the expansion, dissolution, and transformation behavior of clay minerals in the rare earth leaching process were studied. The results showed that rare earth leaching efficiency followed the order ammonium acetate > ammonium chloride > ammonium sulfate, with values of 90.60%, 85.96%, and 84.12%, respectively. The swelling ratio of clay mineral followed the order ammonium acetate < ammonium chloride < ammonium sulfate; the clay mineral swelling ratio was 2.09% when ammonium acetate was the leaching agent. Thermogravimetric analysis showed that the interlayer water content was the lowest when ammonium acetate was used as the leaching agent. Under the conditions of different leaching agents, the clay mineral contents changed from illite and halloysite to smectite and kaolinite. When ammonium acetate was used as the leaching agent, the relative conversion of illite was 1.49%, and that of smectite was only 0.17%. SEM analysis showed that the clay minerals expanded and dissolved obviously when ammonium chloride and ammonium sulfate were used as the leaching agents. Meanwhile, the clay mineral layered structure was relatively complete when ammonium acetate was used as the leaching agent. Therefore, when ammonium acetate was used as the leaching agent, it had the least effect on the swelling, dissolution, and transformation of clay minerals. This can provide a theoretical basis for the safe production of weathered crust elution-deposited rare earth ore, and for the screening of green and efficient leaching agents. Full article
(This article belongs to the Special Issue Advances in Mineral Processing and Hydrometallurgy—2nd Edition)
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15 pages, 12124 KiB  
Article
Influence of Flow-Gas Composition on Reaction Products of Thermally Treated NMC Battery Black Mass
by Christin Stallmeister and Bernd Friedrich
Metals 2023, 13(5), 923; https://doi.org/10.3390/met13050923 - 10 May 2023
Cited by 5 | Viewed by 2442
Abstract
The recycling of lithium-ion batteries (LIBs) is becoming increasingly important regarding the expansion of electromobility and aspects of raw material supply. Pre-treatment and liberation are crucial for a sufficient recovery of all relevant materials from LIBs. Organic removal and phase transformations by thermal [...] Read more.
The recycling of lithium-ion batteries (LIBs) is becoming increasingly important regarding the expansion of electromobility and aspects of raw material supply. Pre-treatment and liberation are crucial for a sufficient recovery of all relevant materials from LIBs. Organic removal and phase transformations by thermal pre-treatment are beneficial in many respects. This study deals with the influence of flow-gas composition on reaction products and water-based lithium recovery after thermal treatment. Therefore, a spent NMC black mass was thermally treated at 610 °C in a moved bed batch reactor under an N2 atmosphere and mixtures of N2 with 2.5% and 5% O2. Since the phase transformation of the lithium content to Li2CO3 is targeted for water leaching, a treatment under a CO2 atmosphere was studied as well. The resulting off-gas was analyzed by FTIR, and the black mass was characterized by XRD. Afterward, water washing of the black mass was carried out for selective lithium recovery. The gained lithium product was analyzed for the purity and phases present. The addition of O2 resulted in reduced reduction reactions of lithium metal oxides and lower Li-yields in the water leaching compared to the other two atmospheres. In the case of CO2, the formation of Li2CO3 is favored compared to LiF, but the Li-yield of 56% is comparable to N2 treatment. Full article
(This article belongs to the Special Issue Advances in Mineral Processing and Hydrometallurgy—2nd Edition)
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17 pages, 8378 KiB  
Article
Enhanced Precipitation of Gibbsite from Sodium Aluminate Solution by Adding Agglomerated Active Al(OH)3 Seed
by Andrei Shoppert, Dmitry Valeev, Konstantin Alekseev and Irina Loginova
Metals 2023, 13(2), 193; https://doi.org/10.3390/met13020193 - 18 Jan 2023
Cited by 3 | Viewed by 3034
Abstract
The addition of active seed for increasing the precipitation rate leads to the formation of fine Al(OH)3 particles that complicates separation of solid from the mother liquor. In this study, the enhanced precipitation of coarse Al(OH)3 from sodium aluminate solution using [...] Read more.
The addition of active seed for increasing the precipitation rate leads to the formation of fine Al(OH)3 particles that complicates separation of solid from the mother liquor. In this study, the enhanced precipitation of coarse Al(OH)3 from sodium aluminate solution using active agglomerated seed was investigated. Aluminum salt (Al2(SO4)3) were used for active agglomerated seed precipitation at the initial of the process. About 50% of precipitation rate was obtained when these agglomerates were used as a seed in the amount of 20 g L−1 at 25 °C within 10 h. The agglomerated active seed and precipitate samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). SEM images showed that agglomerates consist of flake-like particles that can be stick together by bayerite (β-Al(OH)3) acting as a binder. The precipitation temperature above 35 °C and the high concentration of free alkali (αk = 1.645Na2Ok/Al2O3 > 3) lead to the agglomerates refinement that can be associated with the bayerite dissolution. Full article
(This article belongs to the Special Issue Advances in Mineral Processing and Hydrometallurgy—2nd Edition)
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12 pages, 3519 KiB  
Article
Ultra-Fine Centrifugal Concentration of Bastnaesite Ore
by Alex Norgren and Corby Anderson
Metals 2021, 11(10), 1501; https://doi.org/10.3390/met11101501 - 23 Sep 2021
Cited by 3 | Viewed by 2099
Abstract
Historically, the ability to effectively separate carbonate gangue from bastnaesite via flotation has frequently proven to be challenging without sacrificing significant rare earth oxide (REO) grade or recovery. However, in light of the fact that the rare earth bearing minerals often exhibit higher [...] Read more.
Historically, the ability to effectively separate carbonate gangue from bastnaesite via flotation has frequently proven to be challenging without sacrificing significant rare earth oxide (REO) grade or recovery. However, in light of the fact that the rare earth bearing minerals often exhibit higher specific gravities than the carbonate gangue, the possibility exists that the use of gravity separation could be used to achieve such a selective separation. This however is complicated by the fact that, in cases such as this study when the liberation size is finer than 50 µm, most traditional gravity separation methods become increasingly challenging. The purposes of this study is to determine the applicability of gravity concentrators to beneficiate bastnaesite from deleterious calcite bearing flotation feed material. Via the use of a UF Falcon, it was possible to achieve rougher gravity REO recoveries approaching the upper 80% range while rejecting on the order of 30% of the total calcium. In terms of purely REO recovery, this represents a significant improvement over results obtained via a traditional Falcon in previously reported studies. Full article
(This article belongs to the Special Issue Advances in Mineral Processing and Hydrometallurgy—2nd Edition)
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15 pages, 3910 KiB  
Article
Recovery of Rare Earth Oxides from Flotation Concentrates of Bastnaesite Ore by Ultra-Fine Centrifugal Concentration
by Alex Norgren and Corby Anderson
Metals 2021, 11(9), 1498; https://doi.org/10.3390/met11091498 - 21 Sep 2021
Cited by 2 | Viewed by 2076
Abstract
Historically, the ability to effectively separate carbonate gangue from bastnaesite via flotation has frequently proven to be challenging without sacrificing significant rare earth oxide (REO) grade or recovery. However, in light of the fact that the rare earth bearing minerals often exhibit higher [...] Read more.
Historically, the ability to effectively separate carbonate gangue from bastnaesite via flotation has frequently proven to be challenging without sacrificing significant rare earth oxide (REO) grade or recovery. However, in light of the fact that the rare earth bearing minerals often exhibit higher specific gravities than the carbonate gangue, the possibility exists that the use of gravity separation could be used to achieve such a selective separation. This however is complicated by the fact that, in cases such as this study when the liberation size is finer than 50 microns, most traditional gravity separation methods become increasingly challenging. The aim of this study is to determine the applicability of centrifugal concentrators to beneficiate ultra-fine (UF) bastnaesite and calcite bearing flotation concentrates. By using a UF Falcon, it was possible to achieve initial gravity REO recoveries exceeding 90% while rejecting on the order of 25% to 35% of the total calcium from an assortment of rougher and cleaner flotation concentrates. Additionally, when additional stages of cleaner UF Falcon gravity separation were operated in an open circuit configuration, it was possible, from an original fine feed of 35 microns containing 50.5% REO and 5.5% Ca, to upgrade up to approximately 59% REO and 2.0% calcium. While not the goal of this study, these results also support previous limited data to suggest that UF Falcons are potentially capable of treating a wider range of materials than they were originally designed for, including feeds rich in heavy mineral content. Full article
(This article belongs to the Special Issue Advances in Mineral Processing and Hydrometallurgy—2nd Edition)
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