Pub Date : 2024-11-02DOI: 10.1016/j.mineng.2024.109083
Yawen Liu , Chengxu Liao , Lin Liu , Xiaping Zhu , Zhihui Chen , Dongxue Ren , Tianfeng Yang , Yonghua Sun
This study focused on the preparation, characterization and photocatalytic performance of a monolithic composite made from vanadium-titanium magnetite tailings and quartz sand. Rhodamine B was used as a pollutant model and the photocatalytic degradation of rhodamine B by the prepared composites was investigated. The results indicated that the composite could effectively degraded Rhodamine B, achieving a degradation rate of 98 % within 20 min under optimal conditions. Investigations on the degradation mechanism revealed that dissolved oxygen, superoxide radicals, and the sensitization of Rhodamine B are crucial to the photocatalytic degradation process of Rhodamine B. These results suggest potential benefits for the comprehensive utilization of vanadium titanomagnetite tailings.
本研究的重点是钒钛磁铁矿尾矿和石英砂整体复合材料的制备、表征和光催化性能。以罗丹明 B 为污染物模型，研究了所制备的复合材料对罗丹明 B 的光催化降解。结果表明，复合材料能有效降解罗丹明 B，在最佳条件下，20 分钟内降解率达到 98%。对降解机理的研究表明，溶解氧、超氧自由基和罗丹明 B 的敏化是罗丹明 B 光催化降解过程的关键。
{"title":"Preparation of vanadium-titanium magnetite tailings/quartz sand monolithic composite and photocatalytic degradation of rhodamine B","authors":"Yawen Liu , Chengxu Liao , Lin Liu , Xiaping Zhu , Zhihui Chen , Dongxue Ren , Tianfeng Yang , Yonghua Sun","doi":"10.1016/j.mineng.2024.109083","DOIUrl":"10.1016/j.mineng.2024.109083","url":null,"abstract":"<div><div>This study focused on the preparation, characterization and photocatalytic performance of a monolithic composite made from vanadium-titanium magnetite tailings and quartz sand. Rhodamine B was used as a pollutant model and the photocatalytic degradation of rhodamine B by the prepared composites was investigated. The results indicated that the composite could effectively degraded Rhodamine B, achieving a degradation rate of 98 % within 20 min under optimal conditions. Investigations on the degradation mechanism revealed that dissolved oxygen, superoxide radicals, and the sensitization of Rhodamine B are crucial to the photocatalytic degradation process of Rhodamine B. These results suggest potential benefits for the comprehensive utilization of vanadium titanomagnetite tailings.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 109083"},"PeriodicalIF":4.9,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572942","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 : 2024-11-02DOI: 10.1016/j.mineng.2024.109081
Chen Xin , Chen Jin-fa , Xiao Xin-lei , Fan Lin , Xiao Yan-fei , Huang Li
The leaching liquor extracted from ion-adsorption type rare earth (RE) ores contains large amounts of aluminum (Al) ions. The neutralization-precipitation method for Al removal results in the loss of large amounts of RE, leading to the waste of RE resources. Preliminary research has shown that the introduction of acetic acid (HAc) during the Al removal process could effectively reduce RE loss. However, there has been no in-depth study on the forms of RE loss during the Al removal process with the neutralization-precipitation method and the function mechanism of HAc. In this paper, the yttrium element was used as a representation of RE for relevant research. It was found that the forms of RE loss mainly include adsorption loss and coprecipitation loss, and the addition of HAc can simultaneously reduce both types of loss. The addition of HAc can generate Y(Ac)2+ and Y(Ac)2+ complexes with Y3+, leading to an increase in the initial precipitation pH of yttrium hydroxide from 6.62 to 6.87, thereby reducing the coprecipitation loss of RE. Additionally, HAc was adsorbed on the aluminum hydroxide (Al(OH)3), which increased the surface potential and decreased the specific surface area of Al(OH)3, thus reducing the adsorption loss of RE. Finally, through precipitation experiments on a mixed solution of aluminum sulfate and yttrium sulfate, it was found that when the neutralization pH was 5.2, the percentage of yttrium lost decreased from 18.91 % to 12.66 % as the concentration of HAc was increased from 0 to 0.012 mol/L. The above function mechanism of HAc was further verified through XPS, SEM-EDS, and other tests on the precipitate.
从离子吸附型稀土（RE）矿石中提取的浸出液含有大量的铝（Al）离子。中和沉淀法脱铝会导致大量稀土流失，造成稀土资源的浪费。初步研究表明，在脱铝过程中引入醋酸（HAc）可有效减少可再生能源的损失。然而，对于中和沉淀法脱铝过程中 RE 的损耗形式以及 HAc 的作用机理还没有深入的研究。本文以钇元素作为 RE 的代表进行了相关研究。研究发现，RE 的损耗形式主要包括吸附损耗和共沉淀损耗，而添加 HAc 可同时减少这两种损耗。HAc的加入可生成Y(Ac)2+和Y(Ac)2+与Y3+的络合物，导致氢氧化钇的初始沉淀pH值从6.62升高到6.87，从而减少了RE的共沉淀损失。此外，HAc 被吸附在氢氧化铝（Al(OH)3）上，使氢氧化铝（Al(OH)3）的表面电位升高，比表面积降低，从而减少了 RE 的吸附损失。最后，通过对硫酸铝和硫酸钇的混合溶液进行沉淀实验发现，当中和 pH 值为 5.2 时，随着 HAc 浓度从 0 摩尔/升增加到 0.012 摩尔/升，钇的损失百分比从 18.91% 降低到 12.66%。通过对沉淀物进行 XPS、SEM-EDS 等测试，进一步验证了 HAc 的上述作用机理。
{"title":"Forms of rare earth loss and the function mechanism of acetic acid in the aluminum removal process of rare earth leaching liquor","authors":"Chen Xin , Chen Jin-fa , Xiao Xin-lei , Fan Lin , Xiao Yan-fei , Huang Li","doi":"10.1016/j.mineng.2024.109081","DOIUrl":"10.1016/j.mineng.2024.109081","url":null,"abstract":"<div><div>The leaching liquor extracted from ion-adsorption type rare earth (RE) ores contains large amounts of aluminum (Al) ions. The neutralization-precipitation method for Al removal results in the loss of large amounts of RE, leading to the waste of RE resources. Preliminary research has shown that the introduction of acetic acid (HAc) during the Al removal process could effectively reduce RE loss. However, there has been no in-depth study on the forms of RE loss during the Al removal process with the neutralization-precipitation method and the function mechanism of HAc. In this paper, the yttrium element was used as a representation of RE for relevant research. It was found that the forms of RE loss mainly include adsorption loss and coprecipitation loss, and the addition of HAc can simultaneously reduce both types of loss. The addition of HAc can generate Y(Ac)<sup>2+</sup> and Y(Ac)<sub>2</sub><sup>+</sup> complexes with Y<sup>3+</sup>, leading to an increase in the initial precipitation pH of yttrium hydroxide from 6.62 to 6.87, thereby reducing the coprecipitation loss of RE. Additionally, HAc was adsorbed on the aluminum hydroxide (Al(OH)<sub>3</sub>), which increased the surface potential and decreased the specific surface area of Al(OH)<sub>3</sub>, thus reducing the adsorption loss of RE. Finally, through precipitation experiments on a mixed solution of aluminum sulfate and yttrium sulfate, it was found that when the neutralization pH was 5.2, the percentage of yttrium lost decreased from 18.91 % to 12.66 % as the concentration of HAc was increased from 0 to 0.012 mol/L. The above function mechanism of HAc was further verified through XPS, SEM-EDS, and other tests on the precipitate.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 109081"},"PeriodicalIF":4.9,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572941","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 : 2024-10-30DOI: 10.1016/j.mineng.2024.109013
Haiping Zhao , Zhiwei Liu , Jingzhi Liu , Xinxing Liang , Xueping Hu , Wenquan Duan , Junsheng Ma , Liqiang Gao , Zifeng Yu , Renman Ruan
This work attempts to clarify the reason for low gold recovery in Carlin-type gold ores flotation by revealing the correlation of interactions between pyrite and dolomite during the oxidation process with flotation performance. In this paper, the sulfur oxidation rate determined by Ion chromatography (IC) was adopted to evaluate the oxidation degrees of the mixed pyrite and dolomite systems. Flotation tests observed that the difference in the floating rate of pyrite and dolomite gradually decreases with the accumulation of oxidation degrees. The normalized Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) identified the homogenization effect that occurs between pyrite and dolomite surface during the oxidation process can change the affinity of the mineral surface towards the xanthate collector. Focused beam reflectance measurement (FBRM), Particle video microscope (PVM), and Extended Derjaguin–Landau–Verwey–Overbeek (E-DLVO) calculation show that the homogenization effect changes the interaction force between oxidized pyrite and dolomite, and caused the adhesion between minerals, ultimately, deteriorated the separation performance of Carlin-type gold deposits. This study can give a more detailed explanation of the reason for poor selectivity in the Carlin-type gold ores flotation.
本文试图通过揭示氧化过程中黄铁矿和白云石之间的相互作用与浮选性能的相关性，来阐明卡林型金矿浮选中金回收率低的原因。本文采用离子色谱法（IC）测定的硫氧化率来评价黄铁矿和白云石混合体系的氧化程度。浮选试验观察到，黄铁矿和白云石的上浮率差异随着氧化度的累积而逐渐减小。归一化傅立叶变换红外光谱（FTIR）和 X 射线光电子能谱（XPS）发现，黄铁矿和白云石表面在氧化过程中产生的均质效应会改变矿物表面对黄原酸盐捕收剂的亲和性。聚焦光束反射测量（FBRM）、颗粒视频显微镜（PVM）和扩展德雅金-兰道-维尔维-奥弗贝克（E-DLVO）计算表明，均化效应改变了氧化黄铁矿和白云石之间的相互作用力，造成矿物之间的粘附，最终恶化了卡林型金矿床的分离性能。这项研究可以更详细地解释卡林型金矿浮选选择性差的原因。
{"title":"Correlation of homogenization effect with flotation separation between oxidized pyrite and dolomite","authors":"Haiping Zhao , Zhiwei Liu , Jingzhi Liu , Xinxing Liang , Xueping Hu , Wenquan Duan , Junsheng Ma , Liqiang Gao , Zifeng Yu , Renman Ruan","doi":"10.1016/j.mineng.2024.109013","DOIUrl":"10.1016/j.mineng.2024.109013","url":null,"abstract":"<div><div>This work attempts to clarify the reason for low gold recovery in Carlin-type gold ores flotation by revealing the correlation of interactions between pyrite and dolomite during the oxidation process with flotation performance. In this paper, the sulfur oxidation rate determined by Ion chromatography (IC) was adopted to evaluate the oxidation degrees of the mixed pyrite and dolomite systems. Flotation tests observed that the difference in the floating rate of pyrite and dolomite gradually decreases with the accumulation of oxidation degrees. The normalized Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) identified the homogenization effect that occurs between pyrite and dolomite surface during the oxidation process can change the affinity of the mineral surface towards the xanthate collector. Focused beam reflectance measurement (FBRM), Particle video microscope (PVM), and Extended Derjaguin–Landau–Verwey–Overbeek (E-DLVO) calculation show that the homogenization effect changes the interaction force between oxidized pyrite and dolomite, and caused the adhesion between minerals, ultimately, deteriorated the separation performance of Carlin-type gold deposits. This study can give a more detailed explanation of the reason for poor selectivity in the Carlin-type gold ores flotation.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 109013"},"PeriodicalIF":4.9,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553823","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 : 2024-10-30DOI: 10.1016/j.mineng.2024.109077
Manjiao Chen , Xinjun Hu , Jianping Tian
The surface composition, coordination environment, and chemical state of arsenopyrite dictate the propensity of the mineral to undergo oxidation, leaching, and flotation separation. Because of this, it is of great significance to study the mechanism by which mechanical ball milling affects the composition and coordination of the surface atoms. In this study, the arsenopyrite powder was ground using ball milling under argon. Then, the composition and oxidation state of the Fe, As, and S atoms on the arsenopyrite surface were characterized by XPS after different ball milling durations. A surface reconstruction model was constructed using density functional theory (DFT) calculations by adsorption of single atoms and multiple atoms onto the (001) surface of arsenopyrite, and the atomic configuration, binding energy, and formation energy of the reconstructed surface were calculated. The results showed that the relative content of Fe atoms raised from 30.3 % to 36.3 % as the duration of ball milling increased from 0 to 2 h, while the relative content of S atoms reduced from 33.33 % to 28.47 % under the same conditions. Furthermore, as the duration of ball milling was extended, there was an enhancement in the oxidation state of the atoms on the surface. In particular, S atoms under prolonged ball milling were converted to S0 (S monomer polymer). The binding energy between S atoms and the ideal surface was significantly greater than the energies between Fe and As atoms and the surface. Furthermore, the binding energy between the reconstruction layer and the ideal surface was positively correlated with the ratio of Fe atoms, with the 1Fe + 3As + 2S structure having the lowest binding energy and the 3Fe + 1As + 2S and 3Fe + 2As + 1S structures having the highest binding energies. When the surface was rich in S atoms, the formation energy of the reconstructed surface was the most negative, indicating the highest surface stability.
{"title":"Elucidating the mechanism of ball milling on surface reconstruction of arsenopyrite: XPS property and theoretical studies","authors":"Manjiao Chen , Xinjun Hu , Jianping Tian","doi":"10.1016/j.mineng.2024.109077","DOIUrl":"10.1016/j.mineng.2024.109077","url":null,"abstract":"<div><div>The surface composition, coordination environment, and chemical state of arsenopyrite dictate the propensity of the mineral to undergo oxidation, leaching, and flotation separation. Because of this, it is of great significance to study the mechanism by which mechanical ball milling affects the composition and coordination of the surface atoms. In this study, the arsenopyrite powder was ground using ball milling under argon. Then, the composition and oxidation state of the Fe, As, and S atoms on the arsenopyrite surface were characterized by XPS after different ball milling durations. A surface reconstruction model was constructed using density functional theory (DFT) calculations by adsorption of single atoms and multiple atoms onto the (001) surface of arsenopyrite, and the atomic configuration, binding energy, and formation energy of the reconstructed surface were calculated. The results showed that the relative content of Fe atoms raised from 30.3 % to 36.3 % as the duration of ball milling increased from 0 to 2 h, while the relative content of S atoms reduced from 33.33 % to 28.47 % under the same conditions. Furthermore, as the duration of ball milling was extended, there was an enhancement in the oxidation state of the atoms on the surface. In particular, S atoms under prolonged ball milling were converted to S<sup>0</sup> (S monomer polymer). The binding energy between S atoms and the ideal surface was significantly greater than the energies between Fe and As atoms and the surface. Furthermore, the binding energy between the reconstruction layer and the ideal surface was positively correlated with the ratio of Fe atoms, with the 1Fe + 3As + 2S structure having the lowest binding energy and the 3Fe + 1As + 2S and 3Fe + 2As + 1S structures having the highest binding energies. When the surface was rich in S atoms, the formation energy of the reconstructed surface was the most negative, indicating the highest surface stability.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 109077"},"PeriodicalIF":4.9,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553838","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 : 2024-10-30DOI: 10.1016/j.mineng.2024.108998
Xuefeng He , Yunji Ding , Zhisheng Shi , Jing Ren , Baohuai Zhao , Chunxiao Zhang , Shengen Zhang
Precious metals (PMs), particularly platinum group metals (PGMs), are of strategic importance due to their high supply–demand imbalance, scarcity, and functionality in high-tech fields. The global supply of PMs is constrained due to the rising demand in clean energy applications. Therefore, the recycling of PMs from secondary resources can effectively alleviate the risk of supply shortages. Pyrometallurgical technologies have attracted considerable interest because of their high recovery efficiency, extensive processing capacity, and minimal wastewater production. To enhance the recovery efficiency of PMs and promote the development of the underlying theories and technologies for pyrometallurgical enrichment, this review provides a comprehensive overview of the distribution behavior of PMs between slag and metal, with a particular focus on gold, silver, platinum, palladium, rhodium, and ruthenium. The factors, including gas partial pressure, temperature, slag composition, matte grade, and halogen elements, which have an influence on PMs distribution coefficients, are considered when designing slag types and setting smelting conditions. The characteristics of e-waste and spent catalysts differ significantly from those of ores. The distribution behaviors of PMs determine the recycling of PMs from spent catalysts and e-waste. Finally, the prospects of pyrometallurgical PMs recycling technologies are presented.
{"title":"A comprehensive review on the distribution behaviors of precious metals through pyrometallurgical processes and implications for recycling","authors":"Xuefeng He , Yunji Ding , Zhisheng Shi , Jing Ren , Baohuai Zhao , Chunxiao Zhang , Shengen Zhang","doi":"10.1016/j.mineng.2024.108998","DOIUrl":"10.1016/j.mineng.2024.108998","url":null,"abstract":"<div><div>Precious metals (PMs), particularly platinum group metals (PGMs), are of strategic importance due to their high supply–demand imbalance, scarcity, and functionality in high-tech fields. The global supply of PMs is constrained due to the rising demand in clean energy applications. Therefore, the recycling of PMs from secondary resources can effectively alleviate the risk of supply shortages. Pyrometallurgical technologies have attracted considerable interest because of their high recovery efficiency, extensive processing capacity, and minimal wastewater production. To enhance the recovery efficiency of PMs and promote the development of the underlying theories and technologies for pyrometallurgical enrichment, this review provides a comprehensive overview of the distribution behavior of PMs between slag and metal, with a particular focus on gold, silver, platinum, palladium, rhodium, and ruthenium. The factors, including gas partial pressure, temperature, slag composition, matte grade, and halogen elements, which have an influence on PMs distribution coefficients, are considered when designing slag types and setting smelting conditions. The characteristics of e-waste and spent catalysts differ significantly from those of ores. The distribution behaviors of PMs determine the recycling of PMs from spent catalysts and e-waste. Finally, the prospects of pyrometallurgical PMs recycling technologies are presented.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 108998"},"PeriodicalIF":4.9,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553822","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 : 2024-10-30DOI: 10.1016/j.mineng.2024.109080
Jianfei Li , Zhenhui Long , Yanglei Geng , Ruifeng Ma , Xiaowei Zhang , Yanhong Hu , Jinxiu Wu , Feng Guo , Wenbin Xin , Xiaoyan Hao , Zhicheng Dong , Fan Xiufeng
The liquid alkali decomposition method represents a relatively clean smelting process for the treatment of the mixed rare earth concentrate derived from Bayan Obo. However, the production process generates a considerable quantity of alkaline wastewater, which presents a significant obstacle to the large-scale application of this process. Accordingly, the reduction and high-value treatment of rare earth alkaline wastewater represents a pressing need and challenge. This paper presents a novel approach to the treatment of rare earth alkaline wastewater, which has the potential to revolutionize the way such wastewater is handled. The proposed method involves a series of processes, including mineral phase transformation, ultrasonic enhanced water washing, causticization treatment, and glass preparation. These processes not only reduced the volume of alkaline wastewater by over 50% compared to traditional treatment methods, but challenged the conventional wisdom surrounding the treatment of alkaline wastewater, resulted in the conversion of NaF, Na3PO4, and Na2CO3 into a mixed calcium salt, which contains CaF2, Ca3(PO4)2, and CaCO3. And the mixed calcium salt can then employed in the preparation of high-performance glass. This process not only circumvents the deficiencies associated with the low purity and value of the final product when NaF, Na3PO4, and Na2CO3 are separated individually, but it also allows for the reuse of the generated NaOH, thereby achieving high-value utilization of the alkaline wastewater. This paper offers valuable insights into the treatment of alkaline wastewater from various rare earth minerals treated by the liquid alkali decomposition method.
{"title":"Enhanced rare earth alkali cake washing and alkaline wastewater disposal via mineral phase transformation and ultrasound","authors":"Jianfei Li , Zhenhui Long , Yanglei Geng , Ruifeng Ma , Xiaowei Zhang , Yanhong Hu , Jinxiu Wu , Feng Guo , Wenbin Xin , Xiaoyan Hao , Zhicheng Dong , Fan Xiufeng","doi":"10.1016/j.mineng.2024.109080","DOIUrl":"10.1016/j.mineng.2024.109080","url":null,"abstract":"<div><div>The liquid alkali decomposition method represents a relatively clean smelting process for the treatment of the mixed rare earth concentrate derived from Bayan Obo. However, the production process generates a considerable quantity of alkaline wastewater, which presents a significant obstacle to the large-scale application of this process. Accordingly, the reduction and high-value treatment of rare earth alkaline wastewater represents a pressing need and challenge. This paper presents a novel approach to the treatment of rare earth alkaline wastewater, which has the potential to revolutionize the way such wastewater is handled. The proposed method involves a series of processes, including mineral phase transformation, ultrasonic enhanced water washing, causticization treatment, and glass preparation. These processes not only reduced the volume of alkaline wastewater by over 50% compared to traditional treatment methods, but challenged the conventional wisdom surrounding the treatment of alkaline wastewater, resulted in the conversion of NaF, Na<sub>3</sub>PO<sub>4</sub>, and Na<sub>2</sub>CO<sub>3</sub> into a mixed calcium salt, which contains CaF<sub>2</sub>, Ca<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>, and CaCO<sub>3</sub>. And the mixed calcium salt can then employed in the preparation of high-performance glass. This process not only circumvents the deficiencies associated with the low purity and value of the final product when NaF, Na<sub>3</sub>PO<sub>4</sub>, and Na<sub>2</sub>CO<sub>3</sub> are separated individually, but it also allows for the reuse of the generated NaOH, thereby achieving high-value utilization of the alkaline wastewater. This paper offers valuable insights into the treatment of alkaline wastewater from various rare earth minerals treated by the liquid alkali decomposition method.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 109080"},"PeriodicalIF":4.9,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553662","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 : 2024-10-29DOI: 10.1016/j.mineng.2024.108978
Felipe D. Sepúlveda , Lorena A. Cortes , María P. Arancibia-Bravo , José Delgado , Freddy A. Lucay , Carlos Chacana , Felipe Galleguillos , Cesar Castellón
Cycle flotation tests have been preferred for obtaining metallurgical projections based on laboratory flotation tests because they can simulate a continuous circuit similar to real flotation plants. However, cycle tests are typically conducted in the laboratory under a limited number of operating conditions, so the behavior of ores in these tests might only partially represent the complexity and variations seen in industry-scale flotation operations. To address this limitation, the current work introduces a methodology that integrates cycle tests with the design of experiments (DoE) and response surface methodology (RSM), as well as stochastic simulation to expand the range of tested conditions and identify optimal regions. The methodology involves four stages: definition and preliminary analysis, construction of metamodels, stochastic simulation, and experimental validation. The proposed approach is illustrated through closed/open cycle tests, covering flotation circuits with rougher, cleaner, and scavenger stages. Various output variables are evaluated, such as weight recovery, overall recovery, kinetics, and concentrate and tail grade. The study reveals that polynomial models were inefficient in fitting the experimental data accurately, leading to the use of Monte Carlo simulation to predict closed-cycle test results, which were later validated experimentally. Ultimately, this research provides valuable recommendations for the appropriate application of DoE and RSM in mineral processing.
循环浮选试验是根据实验室浮选试验获得冶金预测的首选方法，因为它们可以模拟与实际浮选厂类似的连续回路。然而，循环试验通常是在实验室有限的操作条件下进行的，因此这些试验中的矿石行为可能只能部分代表工业规模浮选操作中的复杂性和变化。为了解决这一局限性，目前的工作引入了一种方法，将循环测试与实验设计 (DoE) 和响应面方法 (RSM) 以及随机模拟相结合，以扩大测试条件的范围并确定最佳区域。该方法包括四个阶段：定义和初步分析、元模型构建、随机模拟和实验验证。建议的方法通过封闭/开放循环测试进行说明，涵盖浮选回路的粗选、精选和扫选阶段。对各种输出变量进行了评估，如重量回收率、总回收率、动力学以及精矿和尾矿品位。研究表明，多项式模型在准确拟合实验数据方面效率不高，因此需要使用蒙特卡罗模拟来预测封闭循环测试结果，随后再通过实验进行验证。最终，这项研究为在矿物加工中适当应用 DoE 和 RSM 提供了宝贵的建议。
{"title":"Optimizing flotation circuits: A comprehensive approach using design of experiments and stochastic simulation in cycle test validation","authors":"Felipe D. Sepúlveda , Lorena A. Cortes , María P. Arancibia-Bravo , José Delgado , Freddy A. Lucay , Carlos Chacana , Felipe Galleguillos , Cesar Castellón","doi":"10.1016/j.mineng.2024.108978","DOIUrl":"10.1016/j.mineng.2024.108978","url":null,"abstract":"<div><div>Cycle flotation tests have been preferred for obtaining metallurgical projections based on laboratory flotation tests because they can simulate a continuous circuit similar to real flotation plants. However, cycle tests are typically conducted in the laboratory under a limited number of operating conditions, so the behavior of ores in these tests might only partially represent the complexity and variations seen in industry-scale flotation operations. To address this limitation, the current work introduces a methodology that integrates cycle tests with the design of experiments (DoE) and response surface methodology (RSM), as well as stochastic simulation to expand the range of tested conditions and identify optimal regions. The methodology involves four stages: definition and preliminary analysis, construction of metamodels, stochastic simulation, and experimental validation. The proposed approach is illustrated through closed/open cycle tests, covering flotation circuits with rougher, cleaner, and scavenger stages. Various output variables are evaluated, such as weight recovery, overall recovery, kinetics, and concentrate and tail grade. The study reveals that polynomial models were inefficient in fitting the experimental data accurately, leading to the use of Monte Carlo simulation to predict closed-cycle test results, which were later validated experimentally. Ultimately, this research provides valuable recommendations for the appropriate application of DoE and RSM in mineral processing.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 108978"},"PeriodicalIF":4.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663426","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 : 2024-10-28DOI: 10.1016/j.mineng.2024.109057
Rayhaan Perin , Stephen W. Peterson , Jonathan P. Shock , Pablo Brito-Parada , Diego Mesa , Katie Cole
A non-invasive technique named positron emission particle tracking (PEPT) is used to study the dynamics of mineral particles found in froth flotation. High frequency tracking is required to fully resolve turbulent flow paths with highly fluctuating velocity components. Tracking frequency is also called “location rate”, which is the number of tracked locations per second. A time interpolation algorithm was implemented on the raw data of a PEPT measurement to increase the effective location rate of PEPT data. The algorithm was validated with Monte-Carlo simulations of the Siemens ECAT “EXACT3D” HR++ PET scanner at PEPT Cape Town (University of Cape Town). The paths generated from the simulated data with improved timing information had an order of magnitude lower uncertainty in both the position and time components of a location measurement. The algorithm was then applied to PEPT experiments with freely moving particles in a laboratory scale flotation vessel to demonstrate the impact of tracking with higher fidelity.
{"title":"Increasing the location rate of positron emission particle tracking (PEPT) measurements for froth flotation","authors":"Rayhaan Perin , Stephen W. Peterson , Jonathan P. Shock , Pablo Brito-Parada , Diego Mesa , Katie Cole","doi":"10.1016/j.mineng.2024.109057","DOIUrl":"10.1016/j.mineng.2024.109057","url":null,"abstract":"<div><div>A non-invasive technique named positron emission particle tracking (PEPT) is used to study the dynamics of mineral particles found in froth flotation. High frequency tracking is required to fully resolve turbulent flow paths with highly fluctuating velocity components. Tracking frequency is also called “location rate”, which is the number of tracked locations per second. A time interpolation algorithm was implemented on the raw data of a PEPT measurement to increase the effective location rate of PEPT data. The algorithm was validated with Monte-Carlo simulations of the Siemens ECAT “EXACT3D” HR++ PET scanner at PEPT Cape Town (University of Cape Town). The paths generated from the simulated data with improved timing information had an order of magnitude lower uncertainty in both the position and time components of a location measurement. The algorithm was then applied to PEPT experiments with freely moving particles in a laboratory scale flotation vessel to demonstrate the impact of tracking with higher fidelity.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 109057"},"PeriodicalIF":4.9,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532854","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 : 2024-10-28DOI: 10.1016/j.mineng.2024.109058
Kobina Akyea Ofori, William Hanson, Kaiwu Huang, Lei Pan
Direct aqueous mineral carbonation of olivine minerals has been extensively investigated in the past. However, the effect of inorganic electrolytes, particularly sodium sulfate (Na2SO4), on mineral carbonation rate has not been investigated yet. In this work, we report experimental results on the CO2 uptake rate of ultrafine olivine-rich rocks using Na2SO4 and sodium chloride (NaCl) as inorganic catalysts under hydrothermal conditions. The reaction mechanism was explained using both a shrinking core model and a machine learning model. One major and unexpected finding was that the use of Na2SO4 significantly increased the carbonation efficiency compared to the baseline with and without using sodium chloride (NaCl) as an inorganic electrolyte. The results showed that an increase in the carbonation kinetics in the presence of Na2SO4 was evident, particularly at a temperature range of 145–185 °C. At this temperature range, the reaction kinetics are predominantly governed by the product layer diffusion control mechanism. The presence of Na2SO4 electrolyte likely contributed to a promoted dissolution of silica and divalent ions from the hosting rocks/minerals. Results obtained from machine learning modelling confirmed that both the temperature and Na2SO4 additive were key parameters for mineral carbonation compared with other process variables. The present study demonstrates the catalyzing role of Na2SO4 in direct aqueous mineral carbonation of olivine minerals.
{"title":"Sulfate-activated mineral carbonation of olivine minerals with mechanisms explained by shrinking core models and by machine learning algorithm","authors":"Kobina Akyea Ofori, William Hanson, Kaiwu Huang, Lei Pan","doi":"10.1016/j.mineng.2024.109058","DOIUrl":"10.1016/j.mineng.2024.109058","url":null,"abstract":"<div><div>Direct aqueous mineral carbonation of olivine minerals has been extensively investigated in the past. However, the effect of inorganic electrolytes, particularly sodium sulfate (Na<sub>2</sub>SO<sub>4</sub>), on mineral carbonation rate has not been investigated yet. In this work, we report experimental results on the CO<sub>2</sub> uptake rate of ultrafine olivine-rich rocks using Na<sub>2</sub>SO<sub>4</sub> and sodium chloride (NaCl) as inorganic catalysts under hydrothermal conditions. The reaction mechanism was explained using both a shrinking core model and a machine learning model. One major and unexpected finding was that the use of Na<sub>2</sub>SO<sub>4</sub> significantly increased the carbonation efficiency compared to the baseline with and without using sodium chloride (NaCl) as an inorganic electrolyte. The results showed that an increase in the carbonation kinetics in the presence of Na<sub>2</sub>SO<sub>4</sub> was evident, particularly at a temperature range of 145–185 °C. At this temperature range, the reaction kinetics are predominantly governed by the product layer diffusion control mechanism. The presence of Na<sub>2</sub>SO<sub>4</sub> electrolyte likely contributed to a promoted dissolution of silica and divalent ions from the hosting rocks/minerals. Results obtained from machine learning modelling confirmed that both the temperature and Na<sub>2</sub>SO<sub>4</sub> additive were key parameters for mineral carbonation compared with other process variables. The present study demonstrates the catalyzing role of Na<sub>2</sub>SO<sub>4</sub> in direct aqueous mineral carbonation of olivine minerals.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 109058"},"PeriodicalIF":4.9,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533312","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 : 2024-10-28DOI: 10.1016/j.mineng.2024.109068
Robson Antunes Caciatori, Alexandre Gonçalves Dal-Bó, Adriano Michael Bernardin
The increase in CO2 emission during Portland cement manufacturing has motivated studies on new binder systems. The production of alternative cements with less environmental impact (zero clinker) has been gaining increasing interest, mainly because green cements emit smaller amounts of CO2. One of these binders, the geopolymers, are obtained from the alkaline activation of materials rich in silica and alumina, being binders with reduced environmental impact. Therefore, the aim of this work was to study the structural (by DSC and FTIR) and compressive strength evolution of a reference, stoichiometric metakaolin by alkaline activation with Na + ions at 28 and 90 days. The effect of sodium ion concentration at room temperature during geopolymerization was observed. A pure, stoichiometric kaolin and the derived metakaolin calcined in a rotary kiln at 800 ˚C were characterized by XRF, XRD, DSC/TG and PSD. Geopolymeric pastes activated with NaOH and Na2SiO3 were made using mixture design. The pastes were characterized by DSC, FTIR in ATR mode and axial compression strength at 28 and 90 days. The DSC analysis showed that the main reactions occur up to 180 min from the beginning of the preparation of the pastes. The main bands identified by FTIR are from the Si-O-T bond and water contained in the pastes. The index of axial compressive strength shows that the geopolymer pastes reached, on average, 90 % of the final strength in up to 14 days. The use of a metakaolin without impurities for SiO2/Al2O3 ratios close to 1.5 resulted in geopolymers with 85 MPa of compressive strength after 28 days of curing.
{"title":"Effect of Na+ alkaline activation on the geopolymerization of a pure metakaolin at room temperature","authors":"Robson Antunes Caciatori, Alexandre Gonçalves Dal-Bó, Adriano Michael Bernardin","doi":"10.1016/j.mineng.2024.109068","DOIUrl":"10.1016/j.mineng.2024.109068","url":null,"abstract":"<div><div>The increase in CO<sub>2</sub> emission during Portland cement manufacturing has motivated studies on new binder systems. The production of alternative cements with less environmental impact (zero clinker) has been gaining increasing interest, mainly because green cements emit smaller amounts of CO<sub>2</sub>. One of these binders, the geopolymers, are obtained from the alkaline activation of materials rich in silica and alumina, being binders with reduced environmental impact. Therefore, the aim of this work was to study the structural (by DSC and FTIR) and compressive strength evolution of a reference, stoichiometric metakaolin by alkaline activation with Na + ions at 28 and 90 days. The effect of sodium ion concentration at room temperature during geopolymerization was observed. A pure, stoichiometric kaolin and the derived metakaolin calcined in a rotary kiln at 800 ˚C were characterized by XRF, XRD, DSC/TG and PSD. Geopolymeric pastes activated with NaOH and Na<sub>2</sub>SiO<sub>3</sub> were made using mixture design. The pastes were characterized by DSC, FTIR in ATR mode and axial compression strength at 28 and 90 days. The DSC analysis showed that the main reactions occur up to 180 min from the beginning of the preparation of the pastes. The main bands identified by FTIR are from the Si-O-T bond and water contained in the pastes. The index of axial compressive strength shows that the geopolymer pastes reached, on average, 90 % of the final strength in up to 14 days. The use of a metakaolin without impurities for SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> ratios close to 1.5 resulted in geopolymers with 85 MPa of compressive strength after 28 days of curing.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 109068"},"PeriodicalIF":4.9,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533313","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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