Pub Date : 2024-10-05DOI: 10.1016/j.mineng.2024.109040
Qiang Guo , Binbin Huo , Kunpeng Yu , Yuanliang Xiong , Baoliang Li
The workability of alkali-activated coal gasification slag (CGS) based backfill materials is critical parameter in transportation processes, while the high water demand of CGS hinders its application due to its high specific surface area. This study utilizes acetic acid (AA) as a preconditioner to modify the surface characteristics of CGS, aiming to optimize the rheology of alkali-activated CGS backfill pastes (AAC). The shear stress, viscosity, thixotropic property, and zeta potential of AAC, and mineral composition and surface morphology of AA-modified CGS at various AA dosages were systematically investigated. It is found that the yield stress, plastic viscosity, and hysteresis loop area of AAC reaches the lowest value at 4 wt% AA dosage on the basis of the CGS, owing to AA reacts with the minerals on the surface of CGS particles, and then the AA is adsorbed on the CGS particles and acts as a surfactant, which increases the static electricity between CGS particles. However, the yield stress of AAC increases significantly when the AA dosage exceeds 4 wt%, attributing to the smaller particle size resulting from AA modification, which raises water demand. This investigation proposes a novel approach for optimizing the rheology of CGS based AAC and provides theoretical guidance for employing modified CGS as backfill materials.
基于碱活化煤气化炉渣（CGS）的回填材料的可操作性是运输过程中的关键参数，而 CGS 的高比表面积使其高需水量阻碍了其应用。本研究利用醋酸（AA）作为前处理剂来改变 CGS 的表面特性，旨在优化碱激活 CGS 回填浆料（AAC）的流变性。系统研究了不同 AA 用量下 AAC 的剪切应力、粘度、触变性和 Zeta 电位，以及 AA 改性 CGS 的矿物组成和表面形态。研究发现，在 CGS 的基础上，当 AA 用量为 4 wt% 时，AAC 的屈服应力、塑性粘度和滞后环面积达到最低值，这是由于 AA 与 CGS 颗粒表面的矿物发生反应，然后 AA 被吸附在 CGS 颗粒上，起到表面活性剂的作用，从而增加了 CGS 颗粒间的静电。然而，当 AA 用量超过 4 wt% 时，AAC 的屈服应力会显著增加，原因是 AA 改性后粒径变小，从而提高了需水量。这项研究提出了一种优化基于 CGS 的 AAC 流变性能的新方法，并为将改性 CGS 用作回填材料提供了理论指导。
{"title":"Using acetic acid as a preconditioner to optimize rheology of alkali-activated coal gasification slag based backfill pastes","authors":"Qiang Guo , Binbin Huo , Kunpeng Yu , Yuanliang Xiong , Baoliang Li","doi":"10.1016/j.mineng.2024.109040","DOIUrl":"10.1016/j.mineng.2024.109040","url":null,"abstract":"<div><div>The workability of alkali-activated coal gasification slag (CGS) based backfill materials is critical parameter in transportation processes, while the high water demand of CGS hinders its application due to its high specific surface area. This study utilizes acetic acid (AA) as a preconditioner to modify the surface characteristics of CGS, aiming to optimize the rheology of alkali-activated CGS backfill pastes (AAC). The shear stress, viscosity, thixotropic property, and zeta potential of AAC, and mineral composition and surface morphology of AA-modified CGS at various AA dosages were systematically investigated. It is found that the yield stress, plastic viscosity, and hysteresis loop area of AAC reaches the lowest value at 4 wt% AA dosage on the basis of the CGS, owing to AA reacts with the minerals on the surface of CGS particles, and then the AA is adsorbed on the CGS particles and acts as a surfactant, which increases the static electricity between CGS particles. However, the yield stress of AAC increases significantly when the AA dosage exceeds 4 wt%, attributing to the smaller particle size resulting from AA modification, which raises water demand. This investigation proposes a novel approach for optimizing the rheology of CGS based AAC and provides theoretical guidance for employing modified CGS as backfill materials.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"218 ","pages":"Article 109040"},"PeriodicalIF":4.9,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-04DOI: 10.1016/j.mineng.2024.109018
Kangkang Sun , Ngoc N. Nguyen , Anh V. Nguyen
Froth flotation uses air bubbles to separate mineral particles based on the difference in mineral surface hydrophobicity. Collectors are needed to selectively hydrophobize the surface of targeted minerals to augment the difference in surface hydrophobicity between wanted minerals and unwanted ones. Here, we showed that this classical (well-established) principle fails to describe the flotation of water-soluble minerals. Our systematic micro-flotation tests using soluble minerals (NaCl and KCl crystals) in brines and three popular collectors (dodecylamine hydrochloride, sodium dodecylsulfate, and sodium laurate) showed a substantial flotation recovery of the salt minerals without detected collector adsorption at the mineral surfaces by X-ray photoelectron spectroscopy (XPS). Complementary particle size distribution measurement indicated the occurrence of sub-micron collector colloids in saturated brines. Moreover, the flotation recovery agreed well with the measured contact angle, suggesting the attraction between bubble-bound collector colloids and salt crystal surfaces. These paradoxical results signify a new principle underlying the flotation of soluble minerals, i.e., the selective colloidal attraction between bubble-bound collector colloids and salt particles enables the flotation separation of soluble minerals.
浮选利用气泡根据矿物表面疏水性的差异来分离矿物颗粒。需要捕收剂来选择性地疏水目标矿物的表面，以增加想要的矿物和不想要的矿物之间的表面疏水性差异。在这里，我们证明了这一经典（已确立的）原理无法描述水溶性矿物的浮选。我们使用盐水中的可溶性矿物（氯化钠和氯化钾晶体）和三种常用的捕收剂（十二烷基胺盐酸盐、十二烷基硫酸钠和月桂酸钠）进行了系统的微浮选试验，结果表明盐类矿物的浮选回收率很高，而且用 X 射线光电子能谱（XPS）检测矿物表面没有捕收剂吸附。粒度分布测量结果表明，饱和盐水中存在亚微米级的捕收剂胶体。此外，浮选回收率与测量的接触角非常吻合，这表明气泡结合的捕收胶体与盐晶体表面之间存在吸引力。这些自相矛盾的结果表明了可溶性矿物浮选的一个新原理，即气泡结合的捕收胶体与盐颗粒之间的选择性胶体吸引力使可溶性矿物得以浮选分离。
{"title":"Soluble mineral flotation paradox: Improved recovery with no sign of collector adsorption on minerals signifies colloidal attraction between bubble-bound collector colloids and mineral particles","authors":"Kangkang Sun , Ngoc N. Nguyen , Anh V. Nguyen","doi":"10.1016/j.mineng.2024.109018","DOIUrl":"10.1016/j.mineng.2024.109018","url":null,"abstract":"<div><div>Froth flotation uses air bubbles to separate mineral particles based on the difference in mineral surface hydrophobicity. Collectors are needed to selectively hydrophobize the surface of targeted minerals to augment the difference in surface hydrophobicity between wanted minerals and unwanted ones. Here, we showed that this classical (well-established) principle fails to describe the flotation of water-soluble minerals. Our systematic micro-flotation tests using soluble minerals (NaCl and KCl crystals) in brines and three popular collectors (dodecylamine hydrochloride, sodium dodecylsulfate, and sodium laurate) showed a substantial flotation recovery of the salt minerals without detected collector adsorption at the mineral surfaces by X-ray photoelectron spectroscopy (XPS). Complementary particle size distribution measurement indicated the occurrence of sub-micron collector colloids in saturated brines. Moreover, the flotation recovery agreed well with the measured contact angle, suggesting the attraction between bubble-bound collector colloids and salt crystal surfaces. These paradoxical results signify a new principle underlying the flotation of soluble minerals, i.e., the selective colloidal attraction between bubble-bound collector colloids and salt particles enables the flotation separation of soluble minerals.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"218 ","pages":"Article 109018"},"PeriodicalIF":4.9,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-04DOI: 10.1016/j.mineng.2024.109023
Anne Mette Tholstrup Bagger , Kristine Bondo Pedersen , Henrik Hansen , Wolfgang Kunther , Pernille Erland Jensen
Re-mining unextracted metals from mine tailings can contribute to sustaining society’s high demand for metals. Electrodialysis (ED) is a promising, yet underdeveloped, extraction technology for mobilizing and transporting particle-bound elements in a suspension slurry. This study investigated ED for extraction of copper (Cu), lead (Pb) and zinc (Zn) from Cu mine tailings (concentration of Cu: 2039 mg/kg, feldspar-dominant) and Pb-Zn mine tailings (Pb: 4469 mg/kg, Zn: 19417 mg/kg, dolomite-dominant). A multivariate experimental design was used to examine the effect of varying current density (1–5 mA/cm2) and operation time (24–336 h) of 40 bench-scale experiments. The maximum extractions obtained were 70 % Cu from the Cu mine tailings and 97 % Pb and 88 % Zn from the Pb-Zn mine tailings. Depending on the tailing, the extraction was influenced differently by current density and operation time. In particular, carbonate minerals such as dolomite and calcite delayed acidification and thus the extraction due to their buffering capacity. However, as the carbonaceous tailings contained a larger proportion of soluble metals, likely to be bound in the carbonates themselves, overall higher metal extraction was obtained from these. Thresholds above, for which the increase of current densities did not increase extraction, were observed at 2 and 4 mA/cm2 for the Cu and Pb-Zn tailings, respectively. The solubility of the remaining metals in the treated tailings increased significantly due to acidification by the EDR process and utilization of the treated tailings in construction materials therefore needs further investigation.
{"title":"Electrodialytic extraction of copper, lead and zinc from sulfide mine tailings: Optimization of current density and operation time","authors":"Anne Mette Tholstrup Bagger , Kristine Bondo Pedersen , Henrik Hansen , Wolfgang Kunther , Pernille Erland Jensen","doi":"10.1016/j.mineng.2024.109023","DOIUrl":"10.1016/j.mineng.2024.109023","url":null,"abstract":"<div><div>Re-mining unextracted metals from mine tailings can contribute to sustaining society’s high demand for metals. Electrodialysis (ED) is a promising, yet underdeveloped, extraction technology for mobilizing and transporting particle-bound elements in a suspension slurry. This study investigated ED for extraction of copper (Cu), lead (Pb) and zinc (Zn) from Cu mine tailings (concentration of Cu: 2039 mg/kg, feldspar-dominant) and Pb-Zn mine tailings (Pb: 4469 mg/kg, Zn: 19417 mg/kg, dolomite-dominant). A multivariate experimental design was used to examine the effect of varying current density (1–5 mA/cm<sup>2</sup>) and operation time (24–336 h) of 40 bench-scale experiments. The maximum extractions obtained were 70 % Cu from the Cu mine tailings and 97 % Pb and 88 % Zn from the Pb-Zn mine tailings. Depending on the tailing, the extraction was influenced differently by current density and operation time. In particular, carbonate minerals such as dolomite and calcite delayed acidification and thus the extraction due to their buffering capacity. However, as the carbonaceous tailings contained a larger proportion of soluble metals, likely to be bound in the carbonates themselves, overall higher metal extraction was obtained from these. Thresholds above, for which the increase of current densities did not increase extraction, were observed at 2 and 4 mA/cm<sup>2</sup> for the Cu and Pb-Zn tailings, respectively. The solubility of the remaining metals in the treated tailings increased significantly due to acidification by the EDR process and utilization of the treated tailings in construction materials therefore needs further investigation.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"218 ","pages":"Article 109023"},"PeriodicalIF":4.9,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1016/j.mineng.2024.109038
Jingyi Hao , Binchuan Li , Jing Dai , Daxue Fu , Yongfeng Chang , Jianshe Chen , Na Xu , Kuiren Liu , Qing Han
The strongly alkaline sodium aluminate solution generated from high-sulfur bauxites during their refinement through the Bayer process contains sulfur, mainly in the form of thiosulfate (S2O32−) ions, which affects the quality of the target product (alumina). Consequently, the large-scale use of high-sulfur bauxites is severely limited, and methods of desulfurizing sodium aluminate solutions are urgently needed. To address this need, we herein prepared metal–organic framework (ZIF-8)-supported Co-doped TiO2 (Co-TiO2@ZIF-8) using a sol–gel method and low-temperature calcination under N2 and examined the ability of this composite to photocatalyze the oxidative degradation of thiosulfate ions in sodium aluminate solutions. Co-TiO2@ZIF-8 retained the large specific surface area and rich porosity of ZIF-8, which reduced the agglomeration of TiO2 particles on the surface. The loading of Co-TiO2 endowed Co-TiO2@ZIF-8 with a mesoporous structure and thus increased its adsorption capacity. Compared with ZIF-8, Co-TiO2@ZIF-8 featured new functional groups, and the formation of Zn–C and N–Ti–O bonds confirmed the successful integration of Co-TiO2 with the ZIF-8 carrier. Consequently, the thiosulfate removal rates by Co-TiO2@ZIF-8 were 42 % and 26 % higher than those observed for the blank sample and pure TiO2 (light source = xenon arc lamp, oxidant = O3, reaction time = 60 min), respectively. This high performance is primarily due to Co doping, which enhanced the efficiency of visible light utilization, and the photogenerated electron–hole pairs on the photocatalyst surface and hydroxyl radicals formed by the interaction of holes with the solution-phase OH− ions.
{"title":"Degradation of thiosulfate ions in sodium aluminate solution photocatalyzed by Co-TiO2@ZIF-8","authors":"Jingyi Hao , Binchuan Li , Jing Dai , Daxue Fu , Yongfeng Chang , Jianshe Chen , Na Xu , Kuiren Liu , Qing Han","doi":"10.1016/j.mineng.2024.109038","DOIUrl":"10.1016/j.mineng.2024.109038","url":null,"abstract":"<div><div>The strongly alkaline sodium aluminate solution generated from high-sulfur bauxites during their refinement through the Bayer process contains sulfur, mainly in the form of thiosulfate (S<sub>2</sub>O<sub>3</sub><sup>2−</sup>) ions, which affects the quality of the target product (alumina). Consequently, the large-scale use of high-sulfur bauxites is severely limited, and methods of desulfurizing sodium aluminate solutions are urgently needed. To address this need, we herein prepared metal–organic framework (ZIF-8)-supported Co-doped TiO<sub>2</sub> (Co-TiO<sub>2</sub>@ZIF-8) using a sol–gel method and low-temperature calcination under N<sub>2</sub> and examined the ability of this composite to photocatalyze the oxidative degradation of thiosulfate ions in sodium aluminate solutions. Co-TiO<sub>2</sub>@ZIF-8 retained the large specific surface area and rich porosity of ZIF-8, which reduced the agglomeration of TiO<sub>2</sub> particles on the surface. The loading of Co-TiO<sub>2</sub> endowed Co-TiO<sub>2</sub>@ZIF-8 with a mesoporous structure and thus increased its adsorption capacity. Compared with ZIF-8, Co-TiO<sub>2</sub>@ZIF-8 featured new functional groups, and the formation of Zn–C and N–Ti–O bonds confirmed the successful integration of Co-TiO<sub>2</sub> with the ZIF-8 carrier. Consequently, the thiosulfate removal rates by Co-TiO<sub>2</sub>@ZIF-8 were 42 % and 26 % higher than those observed for the blank sample and pure TiO<sub>2</sub> (light source = xenon arc lamp, oxidant = O<sub>3</sub>, reaction time = 60 min), respectively. This high performance is primarily due to Co doping, which enhanced the efficiency of visible light utilization, and the photogenerated electron–hole pairs on the photocatalyst surface and hydroxyl radicals formed by the interaction of holes with the solution-phase OH<sup>−</sup> ions.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"218 ","pages":"Article 109038"},"PeriodicalIF":4.9,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1016/j.mineng.2024.109025
Hyunjin Na , Yuik Eom , Kyoungkeun Yoo , Richard Diaz Alorro
Reprocessing sulfide minerals in tailings is an attractive option for sustainable tailings management. It can reduce the environmental impact generated by acid mine drainage while recovering valuable metals from tailings. Conventional mineral processing techniques often face challenges when it comes to reprocessing mine tailings, primarily due to factors such as particle size and surface oxidation. By addressing these challenges with targeted strategies, it’s possible to improve recovery efficiencies and make the reprocessing of mine tailings more economically viable and environmentally sustainable. Various advanced techniques are able to target specific tailing properties and achieve high recovery efficiency. This review paper covers various conventional mineral processing methods and their technological advances for reprocessing tailings as follows: (1) flotation with novel machines and reagents, (2) advanced gravity separation, (3) centrifugal dense medium separation, and (4) high-gradient magnetic separation.
{"title":"A review on the reprocessing of sulfide tailings for resource recovery and AMD prevention using mineral processing methods","authors":"Hyunjin Na , Yuik Eom , Kyoungkeun Yoo , Richard Diaz Alorro","doi":"10.1016/j.mineng.2024.109025","DOIUrl":"10.1016/j.mineng.2024.109025","url":null,"abstract":"<div><div>Reprocessing sulfide minerals in tailings is an attractive option for sustainable tailings management. It can reduce the environmental impact generated by acid mine drainage while recovering valuable metals from tailings. Conventional mineral processing techniques often face challenges when it comes to reprocessing mine tailings, primarily due to factors such as particle size and surface oxidation. By addressing these challenges with targeted strategies, it’s possible to improve recovery efficiencies and make the reprocessing of mine tailings more economically viable and environmentally sustainable. Various advanced techniques are able to target specific tailing properties and achieve high recovery efficiency. This review paper covers various conventional mineral processing methods and their technological advances for reprocessing tailings as follows: (1) flotation with novel machines and reagents, (2) advanced gravity separation, (3) centrifugal dense medium separation, and (4) high-gradient magnetic separation.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"218 ","pages":"Article 109025"},"PeriodicalIF":4.9,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1016/j.mineng.2024.109036
Daniel Lay , Fengnian Shi , Christian Antonio , Mengbing He
High Voltage Pulse (HVP) enabled ore pre-concentration can potentially provide large energy savings and the ability to upgrade low-grade ores for the mining industry. Two types of pulse generator systems commonly used in HVP breakage are Marx generators and pulse transformers. This initial assessment compares the pre-concentration performance of a SelFrag Lab Unit (utilising a Marx generator) and a custom-built HVP machine (employing a pulse transformer) from Huazhong University of Science and Technology (HUST). Eight sets of experimental results using the two generator systems were collected. Two approaches were taken to analyse the data; a trendline approach using all eight sets of data, and a single-point comparison approach with matched specific energy inputs. The results show that there are significant differences in pre-concentration efficiencies with the HUST machine performing better. To elucidate the potential causes, the degree of size reduction (t10), breakage probability, and selective breakage were investigated for the two generator systems. It is likely that the efficiency of selective breakage is one of the major causes, with the HUST machine presenting better results at selectively breaking high-grade particles and consuming less energy. Additionally, the two generator systems have different energy per discharge levels; the effect of this difference should be investigated in future work.
{"title":"A comparison of ore pre-concentration efficiency between two high voltage pulse generator systems","authors":"Daniel Lay , Fengnian Shi , Christian Antonio , Mengbing He","doi":"10.1016/j.mineng.2024.109036","DOIUrl":"10.1016/j.mineng.2024.109036","url":null,"abstract":"<div><div>High Voltage Pulse (HVP) enabled ore pre-concentration can potentially provide large energy savings and the ability to upgrade low-grade ores for the mining industry. Two types of pulse generator systems commonly used in HVP breakage are Marx generators and pulse transformers. This initial assessment compares the pre-concentration performance of a SelFrag Lab Unit (utilising a Marx generator) and a custom-built HVP machine (employing a pulse transformer) from Huazhong University of Science and Technology (HUST). Eight sets of experimental results using the two generator systems were collected. Two approaches were taken to analyse the data; a trendline approach using all eight sets of data, and a single-point comparison approach with matched specific energy inputs. The results show that there are significant differences in pre-concentration efficiencies with the HUST machine performing better. To elucidate the potential causes, the degree of size reduction (t<sub>10</sub>), breakage probability, and selective breakage were investigated for the two generator systems. It is likely that the efficiency of selective breakage is one of the major causes, with the HUST machine presenting better results at selectively breaking high-grade particles and consuming less energy. Additionally, the two generator systems have different energy per discharge levels; the effect of this difference should be investigated in future work.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"218 ","pages":"Article 109036"},"PeriodicalIF":4.9,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.mineng.2024.109033
Mehrdad Kordloo, Hadi Abdollahi, Mahdi Gharabaghi, Ali Yadollahi, Ali Rezaei, Minoo Ghanbarzad
The roasting-leaching-electrowinning (RLE) process is the most common method for processing sphalerite concentrate. However, this method has disadvantages that can affect the environment. Bioleaching is an eco-friendly method that can replace this method, but the low kinetics of this method is the main barrier to replacing it. In previous research, various additives have been used to solve this problem, but unfortunately, these additives have usually been investigated in low-density pulp, and very limited research has been conducted on the comparison between additives. In this study, the effect of graphite, silver (Ag+), L-cysteine, pyrite, elemental sulfur, and ferrous sulfate additives on the bioleaching of Cd-bearing sphalerite concentrate at 12 % density pulp has been investigated. The results showed that Ag + ions had a higher dissolution rate than the others, and in the optimal condition (60 mg/l), zinc and cadmium extractions were achieved at 82.6 % and 74.5 %, respectively. The bioleached residues have been investigated by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analyses, and it was found that Ag+ ions cause the surface to become porous.
{"title":"Comparing additives effects on bioleaching efficiency of Cd-bearing ZnS concentrate in mesophilic conditioning at high pulp density","authors":"Mehrdad Kordloo, Hadi Abdollahi, Mahdi Gharabaghi, Ali Yadollahi, Ali Rezaei, Minoo Ghanbarzad","doi":"10.1016/j.mineng.2024.109033","DOIUrl":"10.1016/j.mineng.2024.109033","url":null,"abstract":"<div><div>The roasting-leaching-electrowinning (RLE) process is the most common method for processing sphalerite concentrate. However, this method has disadvantages that can affect the environment. Bioleaching is an eco-friendly method that can replace this method, but the low kinetics of this method is the main barrier to replacing it. In previous research, various additives have been used to solve this problem, but unfortunately, these additives have usually been investigated in low-density pulp, and very limited research has been conducted on the comparison between additives. In this study, the effect of graphite, silver (Ag<sup>+</sup>), L-cysteine, pyrite, elemental sulfur, and ferrous sulfate additives on the bioleaching of Cd-bearing sphalerite concentrate at 12 % density pulp has been investigated. The results showed that Ag + ions had a higher dissolution rate than the others, and in the optimal condition (60 mg/l), zinc and cadmium extractions were achieved at 82.6 % and 74.5 %, respectively. The bioleached residues have been investigated by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analyses, and it was found that Ag<sup>+</sup> ions cause the surface to become porous.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"218 ","pages":"Article 109033"},"PeriodicalIF":4.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.mineng.2024.109031
Jason Glas, Dimitre Karamanev
Iron sulfate solutions and the extremophile lifeforms that can live within them are industrially and environmentally important in many applications and require proper assessments of solution properties. Determination of saturated dissolved oxygen concentration is an important parameter for monitoring iron biooxidation processes. However, its determination is not so straight forward using commercially available dissolved oxygen meters. Such meters utilize internal calculation models based on the saline properties of seawater which can be easily overlooked. A method for determination of the saturated dissolved oxygen concentration in acidic iron sulfate solutions with the inclusion of other inorganic salts is proposed in this work using the biooxidation of ferrous iron as an indicator measured with redox potential and converted to oxygen concentration through bioreaction stoichiometry. The technique was tested on a BioGenerator system over the course of four days and proved satisfactory in establishing a value for the saturated dissolved oxygen concentration of the bioreactor broth. Study of the lifespan properties of the microorganisms in absence of ferrous iron substrate was briefly examined to determine the effective handling period of solutions for assessment.
{"title":"Determination of saturated dissolved oxygen concentration in iron sulfate solutions containing iron oxidizing microorganisms","authors":"Jason Glas, Dimitre Karamanev","doi":"10.1016/j.mineng.2024.109031","DOIUrl":"10.1016/j.mineng.2024.109031","url":null,"abstract":"<div><div>Iron sulfate solutions and the extremophile lifeforms that can live within them are industrially and environmentally important in many applications and require proper assessments of solution properties. Determination of saturated dissolved oxygen concentration is an important parameter for monitoring iron biooxidation processes. However, its determination is not so straight forward using commercially available dissolved oxygen meters. Such meters utilize internal calculation models based on the saline properties of seawater which can be easily overlooked. A method for determination of the saturated dissolved oxygen concentration in acidic iron sulfate solutions with the inclusion of other inorganic salts is proposed in this work using the biooxidation of ferrous iron as an indicator measured with redox potential and converted to oxygen concentration through bioreaction stoichiometry. The technique was tested on a BioGenerator system over the course of four days and proved satisfactory in establishing a value for the saturated dissolved oxygen concentration of the bioreactor broth. Study of the lifespan properties of the microorganisms in absence of ferrous iron substrate was briefly examined to determine the effective handling period of solutions for assessment.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"218 ","pages":"Article 109031"},"PeriodicalIF":4.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.mineng.2024.109037
Yuanmin Zou , Alexander Chernyaev , Sipi Seisko , Jani Sainio , Mari Lundström
There is a need to develop removal strategies for typical battery impurities–iron and aluminum–from actual hydrometallurgical recycling solutions. In this work, the investigated solution originated from lithium nickel manganese cobalt oxide (NMC) rich black mass, while iron phosphate (LFP) was used as an in situ reductant. It was found that the presence of phosphate ions supported selective iron precipitation already at pH = 2.0 (T = 60 °C, t = 3 h, NaOH), with nearly complete iron removal (97.8 %). The precipitate was rich in iron (21.5 wt%) and phosphorus (13.4 wt%); it also contained 0.7 wt% Ni and 0.3–0.4 wt% Mn, Co, Al, and Li. It is suggested that the presence of phosphate in minor amounts may cause this co-precipitation of battery metals. With the aim of combined precipitation of iron (100 %) and aluminum (91.0 %), the pH was increased up to 4.5. Although 90.8 % of fluoride precipitated, the remaining fluorides may have kept the aluminum partially in soluble form as Al-F complexes. The formed precipitate had lower iron (18.4 wt%) and phosphorus (11.4 wt%) content, whereas the impurity contents and thus the battery metals losses were slightly higher: Ni, Mn, Co, Al, and Cu were each between 1.1–1.9 wt% and Li and F < 1 wt%. In the precipitates investigated, iron was found predominantly as iron phosphate (FePO4), whereas a minor fraction also precipitated as iron fluoride (FeF3). The precipitated aluminum existed mainly as AlOOH. The results presented here will help to build iron and aluminum removal strategies for industrial battery recycling solutions, and also provide insights into the dominant iron and aluminum phases forming the precipitates.
{"title":"Removal of iron and aluminum from hydrometallurgical NMC-LFP recycling process through precipitation","authors":"Yuanmin Zou , Alexander Chernyaev , Sipi Seisko , Jani Sainio , Mari Lundström","doi":"10.1016/j.mineng.2024.109037","DOIUrl":"10.1016/j.mineng.2024.109037","url":null,"abstract":"<div><div>There is a need to develop removal strategies for typical battery impurities–iron and aluminum–from actual hydrometallurgical recycling solutions. In this work, the investigated solution originated from lithium nickel manganese cobalt oxide (NMC) rich black mass, while iron phosphate (LFP) was used as an in situ reductant. It was found that the presence of phosphate ions supported selective iron precipitation already at pH = 2.0 (<em>T</em> = 60 °C, <em>t</em> = 3 h, NaOH), with nearly complete iron removal (97.8 %). The precipitate was rich in iron (21.5 wt%) and phosphorus (13.4 wt%); it also contained 0.7 wt% Ni and 0.3–0.4 wt% Mn, Co, Al, and Li. It is suggested that the presence of phosphate in minor amounts may cause this co-precipitation of battery metals. With the aim of combined precipitation of iron (100 %) and aluminum (91.0 %), the pH was increased up to 4.5. Although 90.8 % of fluoride precipitated, the remaining fluorides may have kept the aluminum partially in soluble form as Al-F complexes. The formed precipitate had lower iron (18.4 wt%) and phosphorus (11.4 wt%) content, whereas the impurity contents and thus the battery metals losses were slightly higher: Ni, Mn, Co, Al, and Cu were each between 1.1–1.9 wt% and Li and F < 1 wt%. In the precipitates investigated, iron was found predominantly as iron phosphate (FePO<sub>4</sub>), whereas a minor fraction also precipitated as iron fluoride (FeF<sub>3</sub>). The precipitated aluminum existed mainly as AlOOH. The results presented here will help to build iron and aluminum removal strategies for industrial battery recycling solutions, and also provide insights into the dominant iron and aluminum phases forming the precipitates.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"218 ","pages":"Article 109037"},"PeriodicalIF":4.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.mineng.2024.109003
C. Bazin , R. Sista , B. Légaré , J. Caron , F. Lavoie
Magnetic separation is used in ore processing to separate the minerals according to their magnetic susceptibility. Particle size also plays a role in the separation although few industrial results are presented in the literature to discuss this matter. Results from sampling industrial Wet Low Intensity Magnetic Separators (WLIMS) and Wet High Intensity Magnetic Separators (WHIMS) for processing an iron ore show that except for the strongly paramagnetic magnetite (Fe3O4), the recovery of minerals decreases with increasing particle size for both WLIMS and WHIMS. The examination of polished sections of the coarse size fractions from the reject streams of the WHIMS does not provide ground to suspect liberation to be responsible for the reduced recovery of coarse particles. Results also show that it is difficult to establish clear relationships between the mineral recoveries and their reported magnetic susceptibilities for WLIMS while for WHIMS a weak trend is observable.
{"title":"Investigation of the effect of mineral composition and size on particle separation in Wet low and high intensities magnetic separators: An industrial case","authors":"C. Bazin , R. Sista , B. Légaré , J. Caron , F. Lavoie","doi":"10.1016/j.mineng.2024.109003","DOIUrl":"10.1016/j.mineng.2024.109003","url":null,"abstract":"<div><div>Magnetic separation is used in ore processing to separate the minerals according to their magnetic susceptibility. Particle size also plays a role in the separation although few industrial results are presented in the literature to discuss this matter. Results from sampling industrial Wet Low Intensity Magnetic Separators (WLIMS) and Wet High Intensity Magnetic Separators (WHIMS) for processing an iron ore show that except for the strongly paramagnetic magnetite (Fe<sub>3</sub>O<sub>4</sub>), the recovery of minerals decreases with increasing particle size for both WLIMS and WHIMS. The examination of polished sections of the coarse size fractions from the reject streams of the WHIMS does not provide ground to suspect liberation to be responsible for the reduced recovery of coarse particles. Results also show that it is difficult to establish clear relationships between the mineral recoveries and their reported magnetic susceptibilities for WLIMS while for WHIMS a weak trend is observable.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"218 ","pages":"Article 109003"},"PeriodicalIF":4.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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