Pub Date : 2024-11-12DOI: 10.1016/j.mineng.2024.109088
Guilherme Otávio dos Santos , Aline Alves da Silva , Lucas José da Silva Nascimento , Maria Fernanda Reis Souza , Rafaela de Oliveira Teixeira Menezes , Francielle Christine Cunha Andrade , Marcelo Siqueira Valle , Antônio Eduardo Clark Peres , Gilberto Rodrigues da Silva
The Brazilian dolomitic itabirites are considered marginal resources and deposited in waste rock dumps as the cationic reverse flotation circuits present limitations to remove carbonate minerals. This work proposes the synthesis and application of N,N-bis(2-hydroxyethyl)oleamide as a collector in the flotation of carbonates present in dolomitic itabirites. Hematite, quartz, calcite, and dolomite samples were characterized by XRPD and XRF, indicating high purity. The novel collector was characterized by NMR, ATR-FTIR, zeta potential and surface tension measurements, whereas its selectivity was evaluated in microflotation tests, and adsorption was studied via zeta potential and ATR-FTIR. The collector showed maximum selectivity in alkaline condition (pH 10) at 50 mg/L, at which only dolomite and calcite were recovered at 74.7 % and 78.1 %, respectively. The adsorption studies were performed at pH 10, showing that the collector adsorbs non-specifically onto dolomite and calcite, but not quartz and hematite, which is consistent with the flotation results. Microflotation tests with a mixed mineral sample in the presence of corn starch confirmed its potential to depress the carbonate minerals, requiring conditioning with collector to take place prior to the addition of depressant. This approach, followed by conditioning with etheramine showed potential to separate dolomite, calcite, and quartz from hematite.
{"title":"Flotation of carbonates from dolomitic iron ore: synthesis, characterization and application of a novel N,N-bis(2-hydroxyethyl)oleamide collector","authors":"Guilherme Otávio dos Santos , Aline Alves da Silva , Lucas José da Silva Nascimento , Maria Fernanda Reis Souza , Rafaela de Oliveira Teixeira Menezes , Francielle Christine Cunha Andrade , Marcelo Siqueira Valle , Antônio Eduardo Clark Peres , Gilberto Rodrigues da Silva","doi":"10.1016/j.mineng.2024.109088","DOIUrl":"10.1016/j.mineng.2024.109088","url":null,"abstract":"<div><div>The Brazilian dolomitic itabirites are considered marginal resources and deposited in waste rock dumps as the cationic reverse flotation circuits present limitations to remove carbonate minerals. This work proposes the synthesis and application of <em>N</em>,<em>N</em>-bis(2-hydroxyethyl)oleamide as a collector in the flotation of carbonates present in dolomitic itabirites. Hematite, quartz, calcite, and dolomite samples were characterized by XRPD and XRF, indicating high purity. The novel collector was characterized by NMR, ATR-FTIR, zeta potential and surface tension measurements, whereas its selectivity was evaluated in microflotation tests, and adsorption was studied via zeta potential and ATR-FTIR. The collector showed maximum selectivity in alkaline condition (pH 10) at 50 mg/L, at which only dolomite and calcite were recovered at 74.7 % and 78.1 %, respectively. The adsorption studies were performed at pH 10, showing that the collector adsorbs non-specifically onto dolomite and calcite, but not quartz and hematite, which is consistent with the flotation results. Microflotation tests with a mixed mineral sample in the presence of corn starch confirmed its potential to depress the carbonate minerals, requiring conditioning with collector to take place prior to the addition of depressant. This approach, followed by conditioning with etheramine showed potential to separate dolomite, calcite, and quartz from hematite.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"220 ","pages":"Article 109088"},"PeriodicalIF":4.9,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665618","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 : 2024-11-09DOI: 10.1016/j.mineng.2024.109065
Diego Mesa , Varun Gowda , Francisco Ortega , Kanishk Bhadani , Noemi Ariza-Rodríguez , Gauti Asbjörnsson , Pablo R. Brito-Parada
In 2020, the European Union officially designated strontium as a Critical Raw Material (CRM) due to its diverse applications and limited global producers, with Spain as one of the primary producers and the only one in the EU. This comprehensive review discusses strontium market dynamics, global reserves, and technological advancements in mineral processing techniques to extract and concentrate its main bearing minerals, celestine (SrSO4) and strontianite (SrCO3). The review highlights the shift in strontium demand, led until the mid-2000s by applications in cathode-ray tube (CRT) glass, to current uses focused on pyrotechnics, ceramic magnets and drilling fluids.
The study evaluates the progression of beneficiation methods, from manual sorting to advanced techniques such as size separation, gravity separation, flotation, and dense media separation, with recent innovations demonstrating enhanced recovery and purity of celestine concentrates. Industrial case studies from various regions, including Spain and China, illustrate significant advances and regional variations in celestine processing, while emphasising the need for further research and transparency in reporting beneficiation methodologies.
Furthermore, the review addresses the gaps and unavailability of environmental impact assessment of strontium production and underscores the importance of improving circularity through recycling, particularly in light of the negligible End-of-Life Recycling Input Rate (EOLRIR) for strontium in the EU. Emerging applications in magnet technology, medicine, and smart materials present new opportunities, potentially reducing reliance on rare-earth elements and fostering innovation.
The paper also explores the anticipated effects of the CRM status of strontium on future demand, highlighting the need for continued research and technological advances in strontium beneficiation to ensure a stable supply chain. The sustained study and optimisation of extraction and processing methodologies are crucial in meeting the demand from evolving industrial applications and addressing current and future challenges in the supply of this CRM.
{"title":"Strontium minerals as critical raw materials — Market dynamics, processing techniques, and future challenges","authors":"Diego Mesa , Varun Gowda , Francisco Ortega , Kanishk Bhadani , Noemi Ariza-Rodríguez , Gauti Asbjörnsson , Pablo R. Brito-Parada","doi":"10.1016/j.mineng.2024.109065","DOIUrl":"10.1016/j.mineng.2024.109065","url":null,"abstract":"<div><div>In 2020, the European Union officially designated strontium as a Critical Raw Material (CRM) due to its diverse applications and limited global producers, with Spain as one of the primary producers and the only one in the EU. This comprehensive review discusses strontium market dynamics, global reserves, and technological advancements in mineral processing techniques to extract and concentrate its main bearing minerals, celestine (SrSO<sub>4</sub>) and strontianite (SrCO<sub>3</sub>). The review highlights the shift in strontium demand, led until the mid-2000s by applications in cathode-ray tube (CRT) glass, to current uses focused on pyrotechnics, ceramic magnets and drilling fluids.</div><div>The study evaluates the progression of beneficiation methods, from manual sorting to advanced techniques such as size separation, gravity separation, flotation, and dense media separation, with recent innovations demonstrating enhanced recovery and purity of celestine concentrates. Industrial case studies from various regions, including Spain and China, illustrate significant advances and regional variations in celestine processing, while emphasising the need for further research and transparency in reporting beneficiation methodologies.</div><div>Furthermore, the review addresses the gaps and unavailability of environmental impact assessment of strontium production and underscores the importance of improving circularity through recycling, particularly in light of the negligible End-of-Life Recycling Input Rate (EOLRIR) for strontium in the EU. Emerging applications in magnet technology, medicine, and smart materials present new opportunities, potentially reducing reliance on rare-earth elements and fostering innovation.</div><div>The paper also explores the anticipated effects of the CRM status of strontium on future demand, highlighting the need for continued research and technological advances in strontium beneficiation to ensure a stable supply chain. The sustained study and optimisation of extraction and processing methodologies are crucial in meeting the demand from evolving industrial applications and addressing current and future challenges in the supply of this CRM.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"220 ","pages":"Article 109065"},"PeriodicalIF":4.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665613","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 : 2024-11-09DOI: 10.1016/j.mineng.2024.109093
Xiaolin Yang , Kefei Zhang , Teng Wang , Guangyuan Xie , Jesse Thé , Zhongchao Tan , Hesheng Yu
Ash content is a key indicator to evaluate coal flotation concentrate quality and adjust flotation process parameters, which could be determined by analyzing froth images. In this research, a multi-scale multi-task neural network (MSTNet) was developed to realize accurate determination of the ash content of industrial coal flotation concentrate by analyzing froth images. Furthermore, transfer learning is used to further improve model accuracy for low-resolution images. Results obtained using industrial data show that MSTNet achieves a higher prediction accuracy while requiring less computations than previous models. It reaches the maximum R2 of 0.9063 with a processing time of 0.0035 seconds per image, while its competitors only reach the maximum R2 of 0.7231 with a processing time of 0.0038 seconds per image. This suggests that MSTNet surpassing its competitors in both accuracy and speed. Furthermore, MSTNet achieves the minimum MAPE of 0.0300, indicating that MSTNet has a mean relative prediction error of ± 3 %. This proves the high prediction accuracy of MSTNet. These results indicate that the proposed MSTNet holds great promise for practical applications. Its practical application will lead to more efficient and intelligent coal production.
{"title":"Multi-scale multi-task neural network combined with transfer learning for accurate determination of the ash content of industrial coal flotation concentrate","authors":"Xiaolin Yang , Kefei Zhang , Teng Wang , Guangyuan Xie , Jesse Thé , Zhongchao Tan , Hesheng Yu","doi":"10.1016/j.mineng.2024.109093","DOIUrl":"10.1016/j.mineng.2024.109093","url":null,"abstract":"<div><div>Ash content is a key indicator to evaluate coal flotation concentrate quality and adjust flotation process parameters, which could be determined by analyzing froth images. In this research, a multi-scale multi-task neural network (MSTNet) was developed to realize accurate determination of the ash content of industrial coal flotation concentrate by analyzing froth images. Furthermore, transfer learning is used to further improve model accuracy for low-resolution images. Results obtained using industrial data show that MSTNet achieves a higher prediction accuracy while requiring less computations than previous models. It reaches the maximum <em>R<sup>2</sup></em> of 0.9063 with a processing time of 0.0035 seconds per image, while its competitors only reach the maximum <em>R<sup>2</sup></em> of 0.7231 with a processing time of 0.0038 seconds per image. This suggests that MSTNet surpassing its competitors in both accuracy and speed. Furthermore, MSTNet achieves the minimum <em>MAPE</em> of 0.0300, indicating that MSTNet has a mean relative prediction error of ± 3 %. This proves the high prediction accuracy of MSTNet. These results indicate that the proposed MSTNet holds great promise for practical applications. Its practical application will lead to more efficient and intelligent coal production.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"220 ","pages":"Article 109093"},"PeriodicalIF":4.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665619","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 : 2024-11-09DOI: 10.1016/j.mineng.2024.109091
Chonghui Zhang , Yihan Su , Tingshu He , Xianzhong Bu , He Wan , Sen Wang , Jiwei Xue
It is of great significance to improve the flotation of copper sulfide minerals at low temperatures. In this study, the reduction mechanism of chalcopyrite flotation performance and the role of copper ions in improving the flotation of chalcopyrite at low temperatures were systematically investigated. The results of the flotation tests prove that the chalcopyrite flotation recovery is lower at low temperatures (5℃) than at room temperatures (20℃), which is directly related to the changes in the surface hydrophobicity. However, the addition of copper ions can effectively improve the chalcopyrite flotation at low temperatures. Electrochemical measurements indicate that copper ions positively affect the redox reaction and electron transport on the chalcopyrite surface at low temperatures, thereby increasing the current density and surface activity of chalcopyrite. Besides, X-ray photoelectron spectroscopy analysis and adsorption measurements clearly indicate that copper ions mainly adsorbed on chalcopyrite surface in the form of CuS species by chemisorption, thereby significantly enhancing the adsorption amounts of xanthate on the chalcopyrite surface and improving the flotation of chalcopyrite at low temperatures.
{"title":"The role of copper ions in improving the flotation of chalcopyrite at low temperatures","authors":"Chonghui Zhang , Yihan Su , Tingshu He , Xianzhong Bu , He Wan , Sen Wang , Jiwei Xue","doi":"10.1016/j.mineng.2024.109091","DOIUrl":"10.1016/j.mineng.2024.109091","url":null,"abstract":"<div><div>It is of great significance to improve the flotation of copper sulfide minerals at low temperatures. In this study, the reduction mechanism of chalcopyrite flotation performance and the role of copper ions in improving the flotation of chalcopyrite at low temperatures were systematically investigated. The results of the flotation tests prove that the chalcopyrite flotation recovery is lower at low temperatures (5℃) than at room temperatures (20℃), which is directly related to the changes in the surface hydrophobicity. However, the addition of copper ions can effectively improve the chalcopyrite flotation at low temperatures. Electrochemical measurements indicate that copper ions positively affect the redox reaction and electron transport on the chalcopyrite surface at low temperatures, thereby increasing the current density and surface activity of chalcopyrite. Besides, X-ray photoelectron spectroscopy analysis and adsorption measurements clearly indicate that copper ions mainly adsorbed on chalcopyrite surface in the form of CuS species by chemisorption, thereby significantly enhancing the adsorption amounts of xanthate on the chalcopyrite surface and improving the flotation of chalcopyrite at low temperatures.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"220 ","pages":"Article 109091"},"PeriodicalIF":4.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665620","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 : 2024-11-09DOI: 10.1016/j.mineng.2024.109076
Paulina Quintanilla , Francisco Fernández , Cristóbal Mancilla , Matías Rojas , Daniel Navia
This study presents the development and validation of a digital twin for a semi-autogenous grinding (SAG) mill controlled by an expert system. The digital twin integrates three key components of the closed-loop operation: (1) fuzzy logic for expert control, (2) a state-space model for regulatory control, and (3) a recurrent neural network to simulate the SAG mill process. The digital twin is combined with a statistical framework for automatically detecting process disturbances (or critical operations), which triggers model retraining only when deviations from expected behavior are identified, ensuring continuous updates with new data to enhance the SAG supervision. The model was trained with 68 h of operational industrial data and validated with an additional 8 h, allowing it to predict mill behavior within a 2.5-min horizon at 30-s intervals with errors smaller than 5%.
本研究介绍了由专家系统控制的半自磨机（SAG）数字孪生系统的开发和验证情况。数字孪生系统集成了闭环操作的三个关键部分：(1) 用于专家控制的模糊逻辑，(2) 用于调节控制的状态空间模型，以及 (3) 用于模拟 SAG 磨机过程的递归神经网络。数字孪生系统与自动检测过程干扰（或关键操作）的统计框架相结合，只有在发现与预期行为有偏差时才会触发模型的重新训练，确保不断更新新数据，以加强对 SAG 的监控。该模型利用 68 小时的工业运行数据进行了训练，并利用另外 8 小时的数据进行了验证，使其能够以 30 秒的间隔预测 2.5 分钟范围内的磨机行为，误差小于 5%。
{"title":"Digital twin with automatic disturbance detection for an expert-controlled SAG mill","authors":"Paulina Quintanilla , Francisco Fernández , Cristóbal Mancilla , Matías Rojas , Daniel Navia","doi":"10.1016/j.mineng.2024.109076","DOIUrl":"10.1016/j.mineng.2024.109076","url":null,"abstract":"<div><div>This study presents the development and validation of a digital twin for a semi-autogenous grinding (SAG) mill controlled by an expert system. The digital twin integrates three key components of the closed-loop operation: (1) fuzzy logic for expert control, (2) a state-space model for regulatory control, and (3) a recurrent neural network to simulate the SAG mill process. The digital twin is combined with a statistical framework for automatically detecting process disturbances (or critical operations), which triggers model retraining only when deviations from expected behavior are identified, ensuring continuous updates with new data to enhance the SAG supervision. The model was trained with 68 h of operational industrial data and validated with an additional 8 h, allowing it to predict mill behavior within a 2.5-min horizon at 30-s intervals with errors smaller than 5%.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"220 ","pages":"Article 109076"},"PeriodicalIF":4.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665611","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 : 2024-11-08DOI: 10.1016/j.mineng.2024.109048
Patrick Rankin , Antonio Di Feo , Sadan Kelebek
Environmental factors and water scarcity have led to the recirculation of greater quantities of water in mineral processing plants. Recycling water or using alternate water sources, e.g. seawater, for flotation can result in an increase in ionic concentrations and lower water quality. Water recirculation and lower water quality can increase ionic strength which can cause corrosion, scale formation, changes in water recovery to the froth phase, precipitation of species on the mineral surfaces causing accidental activation or passivation, agglomeration of particles (double layer compression), loss in selectivity in flotation-lower grade and recovery, froth persistence, and impact bubble-particle interaction. However, in certain cases the effect of ionic strength is not the main factor affecting flotation; reagent type and dosage can have a more significant impact. The ionic species, temperature and their interactions can affect flotation significantly. Certain ionic species like sulfate, sodium, calcium, base metals, chlorine and thiosulphates have threshold concentrations. If these concentration are exceeded, flotation would be negatively effected. The solution chemistry of dissolved species and ionic strength in water is discussed in terms of effects on decay length (double layer compression) on particles, froth properties, threshold concentrations, water film destabilisation, water recovery to froth phase, bubble properties, surface chemistry (precipitates formation and adhesion on particles) and metallurgy. The effects of ionic strength, temperature, species in solution and their interactions on mineral flotation, and sources of variation in water quality are also presented in this article. This review will serve as fundamental knowledge for further study on the effects of water quality. Research gaps and challenges are also discussed.
{"title":"Ionic strength of flotation medium and consequential effects","authors":"Patrick Rankin , Antonio Di Feo , Sadan Kelebek","doi":"10.1016/j.mineng.2024.109048","DOIUrl":"10.1016/j.mineng.2024.109048","url":null,"abstract":"<div><div>Environmental factors and water scarcity have led to the recirculation of greater quantities of water in mineral processing plants. Recycling water or using alternate water sources, e.g. seawater, for flotation can result in an increase in ionic concentrations and lower water quality. Water recirculation and lower water quality can increase ionic strength which can cause corrosion, scale formation, changes in water recovery to the froth phase, precipitation of species on the mineral surfaces causing accidental activation or passivation, agglomeration of particles (double layer compression), loss in selectivity in flotation-lower grade and recovery, froth persistence, and impact bubble-particle interaction. However, in certain cases the effect of ionic strength is not the main factor affecting flotation; reagent type and dosage can have a more significant impact. The ionic species, temperature and their interactions can affect flotation significantly. Certain ionic species like sulfate, sodium, calcium, base metals, chlorine and thiosulphates have threshold concentrations. If these concentration are exceeded, flotation would be negatively effected. The solution chemistry of dissolved species and ionic strength in water is discussed in terms of effects on decay length (double layer compression) on particles, froth properties, threshold concentrations, water film destabilisation, water recovery to froth phase, bubble properties, surface chemistry (precipitates formation and adhesion on particles) and metallurgy. The effects of ionic strength, temperature, species in solution and their interactions on mineral flotation, and sources of variation in water quality are also presented in this article. This review will serve as fundamental knowledge for further study on the effects of water quality. Research gaps and challenges are also discussed.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"220 ","pages":"Article 109048"},"PeriodicalIF":4.9,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665612","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}
Fluidized bed flotation involves three phases of gas, liquid and solid, which can be used for the separation of coarse minerals. In this study, a two-dimensional gas–liquid-solid fluidized bed was developed to explore the fluidization characteristics of fluidized bed flotation. The effects of water velocity, air velocity, frother dosage and particle size (Ql, Qg, ρn, Dp) on the average pressure drop (–ΔP) and standard deviation (σΔP) were investigated. As the water velocity increases, the pressure drop initially increases, subsequently decreases and eventually remains constant. Increasing the air velocity will enhance the resistance of the bed to the water flow, resulting in a reduction in the water velocity required by peak pressure drop. Furthermore, the pressure drop is observed to decrease due to an increase in air velocity after reaching complete fluidization. Increasing the particle size has the opposite effect, while variations in frother dosage only influence the peak pressure drop. According to the bubble behavior, the influence of different conditions on the pressure drop fluctuation was analyzed. Increasing the water velocity, the frother dosage and the particle size contribute to a reduction in pressure drop fluctuation, whereas an increase in air velocity has the opposite effect. When the water velocity exceeds 1.2 L/min and the frother dosage exceeds 80 g/t, the pressure drop fluctuation is basically unchanged. Finally, the response surface methodology was used to analyze the interaction among the variables, and a mathematical model of the correlation coefficient was established to predict effects.
{"title":"Study on fluidization characteristic of fluidized-bed flotation based on multi factor","authors":"Qinglin Yin , Hongji Chen , Shihao Ding , Qi He , Xiahui Gui , Yaowen Xing","doi":"10.1016/j.mineng.2024.109086","DOIUrl":"10.1016/j.mineng.2024.109086","url":null,"abstract":"<div><div>Fluidized bed flotation involves three phases of gas, liquid and solid, which can be used for the separation of coarse minerals. In this study, a two-dimensional gas–liquid-solid fluidized bed was developed to explore the fluidization characteristics of fluidized bed flotation. The effects of water velocity, air velocity, frother dosage and particle size (Q<sub>l</sub>, Q<sub>g</sub>, ρ<sub>n</sub>, D<sub>p</sub>) on the average pressure drop (–ΔP) and standard deviation (σ<sub>ΔP</sub>) were investigated. As the water velocity increases, the pressure drop initially increases, subsequently decreases and eventually remains constant. Increasing the air velocity will enhance the resistance of the bed to the water flow, resulting in a reduction in the water velocity required by peak pressure drop. Furthermore, the pressure drop is observed to decrease due to an increase in air velocity after reaching complete fluidization. Increasing the particle size has the opposite effect, while variations in frother dosage only influence the peak pressure drop. According to the bubble behavior, the influence of different conditions on the pressure drop fluctuation was analyzed. Increasing the water velocity, the frother dosage and the particle size contribute to a reduction in pressure drop fluctuation, whereas an increase in air velocity has the opposite effect. When the water velocity exceeds 1.2 L/min and the frother dosage exceeds 80 g/t, the pressure drop fluctuation is basically unchanged. Finally, the response surface methodology was used to analyze the interaction among the variables, and a mathematical model of the correlation coefficient was established to predict effects.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"220 ","pages":"Article 109086"},"PeriodicalIF":4.9,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665621","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 : 2024-11-08DOI: 10.1016/j.mineng.2024.109089
Longxia Jiang , Bo Feng , Tao Wang , Ziming Wang
Fluorite and barite share similar physicochemical properties, making them challenging to separate efficiently using flotation. To address this problem, sodium oleate (NaOL) was used as a collector to study the separation effect of carboxylated chitosan (CCS) as a depressant for fluorite and barite. Infrared Spectroscopy (FTIR) test, X-ray photoelectron spectroscopy (XPS), Zeta potential test, contact angle test and adsorption test were investigate the selective depression mechanism of CCS. The test results showed that CCS, acting as the depressant, effectively depressed fluorite and separated fluorite and barite. According to mechanistic analysis, CCS developed stable chemisorption by bonding the carboxyl group (–COOH) in its molecule and the calcium sites of fluorite. In contrast, CCS adsorption on barite was a hydrogen bonding interaction, making CCS easily fall off the barite surface. As a result, NaOL can be stably adsorbed on the barite surface, whereas CCS present on the fluorite surface consumes a high number of Ca sites and reduces Ca sites available for NaOL adsorption, resulting in distinct hydrophobicity and floatability differences between fluorite and barite. Consequently, barite and fluorite were successfully separated.
萤石和重晶石具有相似的物理化学特性，因此使用浮选法对它们进行有效分离具有挑战性。为解决这一问题，研究人员使用油酸钠（NaOL）作为捕收剂，研究了羧基化壳聚糖（CCS）作为抑制剂对萤石和重晶石的分离效果。通过红外光谱（FTIR）测试、X 射线光电子能谱（XPS）、Zeta 电位测试、接触角测试和吸附测试研究了 CCS 的选择性抑制机理。试验结果表明，CCS 作为抑制剂能有效抑制萤石，并分离萤石和重晶石。根据机理分析，CCS 是通过其分子中的羧基（-COOH）与萤石的钙位点结合而形成稳定的化学吸附。相反，CCS 在重晶石上的吸附是一种氢键作用，使 CCS 很容易从重晶石表面脱落。因此，NaOL 可以稳定地吸附在重晶石表面，而存在于萤石表面的 CCS 则消耗了大量的 Ca 位点，减少了可用于吸附 NaOL 的 Ca 位点，从而导致萤石和重晶石之间存在明显的疏水性和可浮性差异。因此，重晶石和萤石被成功分离。
{"title":"Selective flotation separation of fluorite and barite with carboxylated chitosan as depressant","authors":"Longxia Jiang , Bo Feng , Tao Wang , Ziming Wang","doi":"10.1016/j.mineng.2024.109089","DOIUrl":"10.1016/j.mineng.2024.109089","url":null,"abstract":"<div><div>Fluorite and barite share similar physicochemical properties, making them challenging to separate efficiently using flotation. To address this problem, sodium oleate (NaOL) was used as a collector to study the separation effect of carboxylated chitosan (CCS) as a depressant for fluorite and barite. Infrared Spectroscopy (FTIR) test, X-ray photoelectron spectroscopy (XPS), Zeta potential test, contact angle test and adsorption test were investigate the selective depression mechanism of CCS. The test results showed that CCS, acting as the depressant, effectively depressed fluorite and separated fluorite and barite. According to mechanistic analysis, CCS developed stable chemisorption by bonding the carboxyl group (–COOH) in its molecule and the calcium sites of fluorite. In contrast, CCS adsorption on barite was a hydrogen bonding interaction, making CCS easily fall off the barite surface. As a result, NaOL can be stably adsorbed on the barite surface, whereas CCS present on the fluorite surface consumes a high number of Ca sites and reduces Ca sites available for NaOL adsorption, resulting in distinct hydrophobicity and floatability differences between fluorite and barite. Consequently, barite and fluorite were successfully separated.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 109089"},"PeriodicalIF":4.9,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663425","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 : 2024-11-08DOI: 10.1016/j.mineng.2024.109085
Yiping Tan , Shuangke Li , Xiaoping Xu , Pan Chen , Zhiyong Gao , Wei Sun , Belinda McFadzean , Jian Cao
Quartz and feldspar are the primary impurities in the mineral processing of pollucite. Due to the highly similar surface properties of these three minerals in terms of physicochemical characteristics, achieving efficient flotation enrichment of pollucite has been a challenging problem. To address this issue, the development of flotation collectors with high selectivity towards pollucite is crucial. In this study, different-sized crown ethers acted as selective collectors for the direct flotation to detach pollucite from feldspar and quartz were investigated, leveraging the selective bonding of crown ethers to alkali metal active site on the surface of pollucite. The properties of 21-crown-7 ether (21C7), benzo-21-crown-7 (B21C7) and dibenzo-21-crown-7 (DB21C7) (with three different cavity sizes) were investigated as collectors for pollucite flotation. The experimental results indicated that DB21C7 exhibited the best collecting performance. The mechanism was studied through various experimental measurements and computational simulations, and the results revealed that the selective adsorption mechanism of crown ethers onto the surface of pollucite was achieved through a combination of chelation interaction involving “spatial effect” and hydrogen bonding interaction. This work has disclosed that crown ether compounds may hold significant potential as collectors for flotation of pollucite.
{"title":"Utilization of crown ether as selective collector for the flotation separation of pollucite from feldspar and quartz","authors":"Yiping Tan , Shuangke Li , Xiaoping Xu , Pan Chen , Zhiyong Gao , Wei Sun , Belinda McFadzean , Jian Cao","doi":"10.1016/j.mineng.2024.109085","DOIUrl":"10.1016/j.mineng.2024.109085","url":null,"abstract":"<div><div>Quartz and feldspar are the primary impurities in the mineral processing of pollucite. Due to the highly similar surface properties of these three minerals in terms of physicochemical characteristics, achieving efficient flotation enrichment of pollucite has been a challenging problem. To address this issue, the development of flotation collectors with high selectivity towards pollucite is crucial. In this study, different-sized crown ethers acted as selective collectors for the direct flotation to detach pollucite from feldspar and quartz were investigated, leveraging the selective bonding of crown ethers to alkali metal active site on the surface of pollucite. The properties of 21-crown-7 ether (21C7), benzo-21-crown-7 (B21C7) and dibenzo-21-crown-7 (DB21C7) (with three different cavity sizes) were investigated as collectors for pollucite flotation. The experimental results indicated that DB21C7 exhibited the best collecting performance. The mechanism was studied through various experimental measurements and computational simulations, and the results revealed that the selective adsorption mechanism of crown ethers onto the surface of pollucite was achieved through a combination of chelation interaction involving “spatial effect” and hydrogen bonding interaction. This work has disclosed that crown ether compounds may hold significant potential as collectors for flotation of pollucite.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"220 ","pages":"Article 109085"},"PeriodicalIF":4.9,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665622","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 : 2024-11-07DOI: 10.1016/j.mineng.2024.109075
Yuhong Fu , Can Wu , Qin Liu , Shanshan Li , Sen Li , Shuai Zhang , Quan Wan
Gold recovery from wastewater should be cost-effective, efficient, and environmentally friendly. In this study, adsorbents containing Fe(II,III) systems were prepared via thermal modification of pyrite. The effects of thermal modification temperature, the source of pyrite, pH, ionic strength, adsorbent solid–liquid ratio, and coexisting metal ions on adsorption were investigated. Further, the removability of iron ions was explored, and multiple adsorption–desorption experiments were conducted to verify the stability and recyclability of the adsorbent. The adsorption law and mechanisms were analyzed using adsorption isotherms, thermodynamics, kinetics, and spectroscopy. The results revealed that the natural pyrite modified at 300°C ( N-Py-300) was a more suitable gold adsorbent with a maximum adsorption of 1055.2 mg/g at 25 °C. When coexisting with other metal ions, N-Py-300 exhibited highly selective adsorption of Au(III). Using a mixture of 10 % thiourea and 2 % HCl as a desorbent facilitated the desorption of almost all Au from N-Py-300, resulting in the recovery of Au and the reuse of N-Py-300. The Fe ions released from the adsorbent were effectively reduced by the addition of Ca(OH)2. The adsorption kinetics and isotherm data were in strong agreement with the pseudo-secondary and Langmuir models, indicating that Au(III) was chemisorbed on N-Py-300 as a monolayer and that Au(III) was reduced to Au(0) and Au(Ⅰ). The pH and IS also affected the adsorption behavior, implying that an electrostatic effect exists. Our findings provide that the thermally modified pyrite can be used to recover precious metals from wastewater efficiently, and provides an experimental basis for the resourceful use of pyrite.
{"title":"Highly efficient recovery of gold by thermally modified pyrite and its mechanism","authors":"Yuhong Fu , Can Wu , Qin Liu , Shanshan Li , Sen Li , Shuai Zhang , Quan Wan","doi":"10.1016/j.mineng.2024.109075","DOIUrl":"10.1016/j.mineng.2024.109075","url":null,"abstract":"<div><div>Gold recovery from wastewater should be cost-effective, efficient, and environmentally friendly. In this study, adsorbents containing Fe(II,III) systems were prepared via thermal modification of pyrite. The effects of thermal modification temperature, the source of pyrite, pH, ionic strength, adsorbent solid–liquid ratio, and coexisting metal ions on adsorption were investigated. Further, the removability of iron ions was explored, and multiple adsorption–desorption experiments were conducted to verify the stability and recyclability of the adsorbent. The adsorption law and mechanisms were analyzed using adsorption isotherms, thermodynamics, kinetics, and spectroscopy. The results revealed that the natural pyrite modified at 300°C ( N-Py-300) was a more suitable gold adsorbent with a maximum adsorption of 1055.2 mg/g at 25 °C. When coexisting with other metal ions, N-Py-300 exhibited highly selective adsorption of Au(III). Using a mixture of 10 % thiourea and 2 % HCl as a desorbent facilitated the desorption of almost all Au from N-Py-300, resulting in the recovery of Au and the reuse of N-Py-300. The Fe ions released from the adsorbent were effectively reduced by the addition of Ca(OH)<sub>2</sub>. The adsorption kinetics and isotherm data were in strong agreement with the pseudo-secondary and Langmuir models, indicating that Au(III) was chemisorbed on N-Py-300 as a monolayer and that Au(III) was reduced to Au(0) and Au(Ⅰ). The pH and IS also affected the adsorption behavior, implying that an electrostatic effect exists. Our findings provide that the thermally modified pyrite can be used to recover precious metals from wastewater efficiently, and provides an experimental basis for the resourceful use of pyrite.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"219 ","pages":"Article 109075"},"PeriodicalIF":4.9,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663423","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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