Pub Date : 2024-11-17DOI: 10.1016/j.mineng.2024.109109
Harish Panghal, Awadhesh Kumar
The increasing demand for sustainable construction materials has driven significant interest in utilizing recycled concrete aggregates (RCA). However, the mechanical performance and durability of RCA are often compromised due to the presence of residual mortar. This study explores an innovative surface treatment approach combining abrasion and cement slurry coating to improve the properties of RCA and enhance the performance of recycled aggregate concrete (RAC). Recycled concrete aggregates were subjected to mechanical abrasion, followed by a cement slurry coating, resulting in the production of Surface-Treated Recycled Concrete Aggregates (STRCA). The study evaluates the impact of STRCA on the compressive strength, drying shrinkage, electrical resistivity, and chloride ion penetration resistance of concrete mixes with varying replacement ratios (25 %, 50 %, 75 %, and 100 %). Results revealed that the water absorption of RCA was significantly reduced from 5.35 % to 2.61 % following the treatment. STRCA 25 and STRCA 50 mixtures exhibited compressive strength increases of 30.16 % and 18.99 % at 7 days, and 29.37 % and 17.13 % at 28 days, respectively. Higher replacement levels (STRCA 75 and STRCA 100) resulted in strength reductions, with 3.91 % and 16.64 % decreases at 7 days. Drying shrinkage increased progressively with higher RCA content, showing 1.72 %, 10.91 %, 25.86 %, and 38.79 % increases at 28 days for STRCA 25, STRCA 50, STRCA 75, and STRCA 100, respectively. Electrical resistivity improved for lower replacement levels, with STRCA 25 showing a 3.41 % increase at 28 days, while STRCA 100 exhibited a 26.25 % reduction. The rapid chloride penetration test results showed that STRCA 100 had the highest resistance to chloride ion penetration, with a 22.72 % and 28.69 % increase in passed charge at 28 and 56 days, respectively, compared to the reference concrete. The findings indicate that surface-treated RCA can enhance the mechanical and durability properties of concrete, especially at lower replacement levels, making it a viable option for sustainable construction.
{"title":"Enhancing durability and strength of concrete through an innovative abrasion and cement slurry treatment of recycled concrete aggregates","authors":"Harish Panghal, Awadhesh Kumar","doi":"10.1016/j.mineng.2024.109109","DOIUrl":"https://doi.org/10.1016/j.mineng.2024.109109","url":null,"abstract":"The increasing demand for sustainable construction materials has driven significant interest in utilizing recycled concrete aggregates (RCA). However, the mechanical performance and durability of RCA are often compromised due to the presence of residual mortar. This study explores an innovative surface treatment approach combining abrasion and cement slurry coating to improve the properties of RCA and enhance the performance of recycled aggregate concrete (RAC). Recycled concrete aggregates were subjected to mechanical abrasion, followed by a cement slurry coating, resulting in the production of Surface-Treated Recycled Concrete Aggregates (STRCA). The study evaluates the impact of STRCA on the compressive strength, drying shrinkage, electrical resistivity, and chloride ion penetration resistance of concrete mixes with varying replacement ratios (25 %, 50 %, 75 %, and 100 %). Results revealed that the water absorption of RCA was significantly reduced from 5.35 % to 2.61 % following the treatment. STRCA 25 and STRCA 50 mixtures exhibited compressive strength increases of 30.16 % and 18.99 % at 7 days, and 29.37 % and 17.13 % at 28 days, respectively. Higher replacement levels (STRCA 75 and STRCA 100) resulted in strength reductions, with 3.91 % and 16.64 % decreases at 7 days. Drying shrinkage increased progressively with higher RCA content, showing 1.72 %, 10.91 %, 25.86 %, and 38.79 % increases at 28 days for STRCA 25, STRCA 50, STRCA 75, and STRCA 100, respectively. Electrical resistivity improved for lower replacement levels, with STRCA 25 showing a 3.41 % increase at 28 days, while STRCA 100 exhibited a 26.25 % reduction. The rapid chloride penetration test results showed that STRCA 100 had the highest resistance to chloride ion penetration, with a 22.72 % and 28.69 % increase in passed charge at 28 and 56 days, respectively, compared to the reference concrete. The findings indicate that surface-treated RCA can enhance the mechanical and durability properties of concrete, especially at lower replacement levels, making it a viable option for sustainable construction.","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"17 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665609","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 : 2024-11-16DOI: 10.1016/j.mineng.2024.109105
S. Pikinini, B. McFadzean, CT O’Connor, X. Zhang
The Bushveld Complex in South Africa contains the largest reserves of platinum group elements (PGEs) in the world. It is composed of the Merensky reef, UG2 reef and the Platreef. Unlike the other reefs that have been largely exploited, the Platreef ores have proved to be difficult to process due to their low content of PGE sulphides and the low association of the PGM minerals with the base metal sulphides. Based on their high association with base metal sulphides in other ores in the Bushveld complex, thiol collectors are used to float PGM minerals. However, relatively high amounts of the PGE arsenide and telluride minerals have been found in the tailing streams of the Platreef concentrators despite being fully liberated. One of the major components in the Platreef ores is sperrylite (PtAs2), which has been found to be slow floating compared to the other PGMs. This study aimed at determining the reasons for the poor floatability of sperrylite with a view to improving its recovery. Tests were conducted to determine the interactions of the mineral with a range of standard and novel collectors. These included microflotation tests to determine the hydrophobicity of the minerals before and after the adsorption of collectors, calorimetric experiments to determine the enthalpy and extent of collector adsorption onto sperrylite, and electrochemical tests to examine charge transfer reactions between sperrylite and the selected standard collectors.
{"title":"Investigating the floatability of sperrylite and its interactions with selected standard and novel collectors","authors":"S. Pikinini, B. McFadzean, CT O’Connor, X. Zhang","doi":"10.1016/j.mineng.2024.109105","DOIUrl":"https://doi.org/10.1016/j.mineng.2024.109105","url":null,"abstract":"The Bushveld Complex in South Africa contains the largest reserves of platinum group elements (PGEs) in the world. It is composed of the Merensky reef, UG2 reef and the Platreef. Unlike the other reefs that have been largely exploited, the Platreef ores have proved to be difficult to process due to their low content of PGE sulphides and the low association of the PGM minerals with the base metal sulphides. Based on their high association with base metal sulphides in other ores in the Bushveld complex, thiol collectors are used to float PGM minerals. However, relatively high amounts of the PGE arsenide and telluride minerals have been found in the tailing streams of the Platreef concentrators despite being fully liberated. One of the major components in the Platreef ores is sperrylite (PtAs<ce:inf loc=\"post\">2</ce:inf>), which has been found to be slow floating compared to the other PGMs. This study aimed at determining the reasons for the poor floatability of sperrylite with a view to improving its recovery. Tests were conducted to determine the interactions of the mineral with a range of standard and novel collectors. These included microflotation tests to determine the hydrophobicity of the minerals before and after the adsorption of collectors, calorimetric experiments to determine the enthalpy and extent of collector adsorption onto sperrylite, and electrochemical tests to examine charge transfer reactions between sperrylite and the selected standard collectors.","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"13 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665614","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}
In this century, our daily life is surrounded by technological devices, and Rare Earth Elements (REE) are at the heart of this technological revolution. They are always listed having the highest supply risk in critical minerals published by different countries. From that point of view, their extraction, and creating a secured supply chain is always crucial. In this research, the influence of calcination conditions on REE extraction from bastnasite ore was studied. Identical leaching in Ethylene Glycol (EG)-FeCl3 media which is one of the Deep Eutectic Solvents (DES) was applied to different calcines to understand calcination parameters on leaching efficiency. After conducting experiments created by Box-Behnken approach with different parameters of temperature, duration, and particles size, the highest Light Rare Earth Elements (LREE) extraction efficiency of 67.22 wt% was achieved at 900° C. However, while conducting control experiments, the highest extraction efficiency was found to be 75.986 wt% as a median of the experiments conducted at 500 °C during 180 min, and with particles finer than 25 µm. This efficiency increase with decreasing temperature is explained by Ce phase transformation from Ce2O3 to CeO2 as proved by XRD analysis. In addition to temperature, particle size was also found highly effective in extraction efficiency especially in Ce extraction. At the experiments conducted at 900 °C, and 270 min but with particles at different size ranges, Ce extraction dramatically dropped from 71.061 wt% to 9.587 wt% at the experiment conducted with finer particles. This lose in efficiency is directly correlated to increasing Ce phase transformation rate due to increasing surface area of fine particles. Non-calcined ore was also leached with DES, and only 10.977 wt% LREE could be extracted. Furthermore, it is concluded that calcination is of vital importance to transform the ore into a soluble form, and temperature, and particle size ranges are found to be two fundamental parameters for tuning the extraction efficiency.
本世纪，我们的日常生活被科技设备所包围，而稀土元素（REE）则是这场科技革命的核心。在各国公布的重要矿产中，稀土元素一直被列为供应风险最高的元素。因此，稀土元素的提取和安全供应链的建立至关重要。在这项研究中，研究了煅烧条件对从膨润土矿中提取稀土元素的影响。在乙二醇（EG）-FeCl3 介质（深共晶溶剂（DES）之一）中对不同的煅烧炉进行了相同的浸出，以了解煅烧参数对浸出效率的影响。在采用方框-贝肯（Box-Behnken）方法，根据温度、持续时间和颗粒大小等不同参数进行实验后，900° C 时的轻稀土元素（LREE）萃取效率最高，达到 67.22 wt%。这种效率随温度降低而提高的原因是 Ce 相从 Ce2O3 转变为 CeO2，XRD 分析证明了这一点。除温度外，颗粒大小对萃取效率也有很大影响，尤其是在萃取 Ce 时。在 900 °C 和 270 分钟的实验中，使用不同粒度的颗粒，萃取效率从 71.061 wt%急剧下降到使用较细颗粒时的 9.587 wt%。效率的下降与细颗粒表面积增大导致 Ce 相变率增加直接相关。非煅烧矿石也用 DES 进行浸出，只能提取 10.977 wt% 的 LREE。此外，还得出结论：煅烧对于将矿石转化为可溶形式至关重要，温度和粒度范围是调整萃取效率的两个基本参数。
{"title":"Influence of calcination conditions on deep eutectic solvents (DES) leaching efficiency of light rare earth elements in bastnasite ore","authors":"S. Samet Kaplan, Cisem Celik Kurtulan, Sebahattin Gurmen, Gokhan Orhan, M.Seref Sonmez","doi":"10.1016/j.mineng.2024.109087","DOIUrl":"https://doi.org/10.1016/j.mineng.2024.109087","url":null,"abstract":"In this century, our daily life is surrounded by technological devices, and Rare Earth Elements (REE) are at the heart of this technological revolution. They are always listed having the highest supply risk in critical minerals published by different countries. From that point of view, their extraction, and creating a secured supply chain is always crucial. In this research, the influence of calcination conditions on REE extraction from bastnasite ore was studied. Identical leaching in Ethylene Glycol (EG)-FeCl<ce:inf loc=\"post\">3</ce:inf> media which is one of the Deep Eutectic Solvents (DES) was applied to different calcines to understand calcination parameters on leaching efficiency. After conducting experiments created by Box-Behnken approach with different parameters of temperature, duration, and particles size, the highest Light Rare Earth Elements (LREE) extraction efficiency of 67.22 wt% was achieved at 900° C. However, while conducting control experiments, the highest extraction efficiency was found to be 75.986 wt% as a median of the experiments conducted at 500 °C during 180 min, and with particles finer than 25 µm. This efficiency increase with decreasing temperature is explained by Ce phase transformation from Ce<ce:inf loc=\"post\">2</ce:inf>O<ce:inf loc=\"post\">3</ce:inf> to CeO<ce:inf loc=\"post\">2</ce:inf> as proved by XRD analysis. In addition to temperature, particle size was also found highly effective in extraction efficiency especially in Ce extraction. At the experiments conducted at 900 °C, and 270 min but with particles at different size ranges, Ce extraction dramatically dropped from 71.061 wt% to 9.587 wt% at the experiment conducted with finer particles. This lose in efficiency is directly correlated to increasing Ce phase transformation rate due to increasing surface area of fine particles. Non-calcined ore was also leached with DES, and only 10.977 wt% LREE could be extracted. Furthermore, it is concluded that calcination is of vital importance to transform the ore into a soluble form, and temperature, and particle size ranges are found to be two fundamental parameters for tuning the extraction efficiency.","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"248 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665617","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 : 2024-11-15DOI: 10.1016/j.mineng.2024.109106
Yingbo Dong, Nuo mingtana, Hai Lin
Hydrophobic modification of sulfur-containing waste rock is a promising strategy for reducing acid mine drainage (AMD) generation. This study investigated the use of sodium oleate and nano silca to modify sulfur-containing waste rock and evaluated the acid-suppressive properties of the sodium oleate and nano silca treatment through static and dynamic leaching tests. Results from these tests indicated that the pH of the leachate from the modified waste rock remained stable above 6.0. The results of 30-day dynamic tests also showed that the inhibition rate of acid generation could be more than 65 % and the reduction rate of total Fe can be more than 85 %. Furthermore, a protective film was formed on the surface of the modified waste rock, and the contact angle was increased to 84.3° compared with the original waste rock (17.9°). Sodium oleate interacted with Fe2+ and Fe3+ to form iron oleate complexes, which were encapsulated on the surface of the waste rock, thus effectively preventing the oxidation of the waste rock and thus inhibiting the generation of acidic water. X-ray photoelectron spectroscopy (XPS) results showed that the C 1 s signal of the modified waste rock sample was enhanced and the characteristic COO-Fe peaks appeared. Additionally, the ratio of the C–C/C–H to O-C = O characteristic peaks increased with the presence of nano silca powder. These findings indicated that ferric oleate complexes facilitated the attachment of nano silca to the surface via van der Waals forces, which filled the pores of the hydrophobic film layer.This study provides a viable solution to the ability of sulphur-containing waste rock to resist oxidation and inhibit acid production.
对含硫废石进行疏水改性是减少酸性矿井排水（AMD）产生的一种可行策略。本研究调查了使用油酸钠和纳米硅卡改性含硫废石的情况，并通过静态和动态浸出试验评估了油酸钠和纳米硅卡处理的抑酸特性。测试结果表明，改性废石浸出液的 pH 值稳定在 6.0 以上。30 天动态试验的结果也表明，酸生成抑制率可达 65% 以上，总铁的减少率可达 85% 以上。此外，改性废石表面形成了一层保护膜，与原始废石（17.9°）相比，接触角增加到 84.3°。油酸钠与 Fe2+ 和 Fe3+ 相互作用，形成油酸铁络合物，包裹在废石表面，从而有效地防止了废石的氧化，从而抑制了酸性水的产生。X 射线光电子能谱（XPS）结果表明，改性废石样品的 C 1 s 信号增强，并出现了特征 COO-Fe 峰。此外，C-C/C-H 与 O-C = O 特征峰的比率随着纳米硅卡粉的存在而增加。这些发现表明，油酸铁络合物通过范德华力促进了纳米硅卡附着到表面，从而填充了疏水膜层的孔隙。这项研究为含硫废石抗氧化和抑制酸生成的能力提供了一个可行的解决方案。
{"title":"Surface hydrophobic modification of sulfur-containing waste rock for the source control acid mine drainage","authors":"Yingbo Dong, Nuo mingtana, Hai Lin","doi":"10.1016/j.mineng.2024.109106","DOIUrl":"https://doi.org/10.1016/j.mineng.2024.109106","url":null,"abstract":"Hydrophobic modification of sulfur-containing waste rock is a promising strategy for reducing acid mine drainage (AMD) generation. This study investigated the use of sodium oleate and nano silca to modify sulfur-containing waste rock and evaluated the acid-suppressive properties of the sodium oleate and nano silca treatment through static and dynamic leaching tests. Results from these tests indicated that the pH of the leachate from the modified waste rock remained stable above 6.0. The results of 30-day dynamic tests also showed that the inhibition rate of acid generation could be more than 65 % and the reduction rate of total Fe can be more than 85 %. Furthermore, a protective film was formed on the surface of the modified waste rock, and the contact angle was increased to 84.3° compared with the original waste rock (17.9°). Sodium oleate interacted with Fe<ce:sup loc=\"post\">2+</ce:sup> and Fe<ce:sup loc=\"post\">3+</ce:sup> to form iron oleate complexes, which were encapsulated on the surface of the waste rock, thus effectively preventing the oxidation of the waste rock and thus inhibiting the generation of acidic water. X-ray photoelectron spectroscopy (XPS) results showed that the C 1 s signal of the modified waste rock sample was enhanced and the characteristic COO-Fe peaks appeared. Additionally, the ratio of the C–C/C–H to O-C = O characteristic peaks increased with the presence of nano silca powder. These findings indicated that ferric oleate complexes facilitated the attachment of nano silca to the surface via van der Waals forces, which filled the pores of the hydrophobic film layer.This study provides a viable solution to the ability of sulphur-containing waste rock to resist oxidation and inhibit acid production.","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"52 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665615","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 : 2024-11-14DOI: 10.1016/j.mineng.2024.109092
Siyuan Wu, Chunhui Gao, Hang Chen, Tuoxiu Wu, Bao Guo, Rongdong Deng, Kaixi Jiang
Flotation is a potential method for extracting residual copper sulfide (CuS) from the acid-leaching residue of copper smelting dust; however, the inhibitory impact of Bi(III) in the flotation pulp significantly hampers its practical application. In this study, we systematically investigated the inhibition mechanism of Bi(III) on CuS flotation and propose a method to prevent inhibition. Microflotation test results show that a pulp environment with pH 3 and a Bi(III) concentration greater than 1 × 10–2 mol/L significantly depresses the floatability of CuS. Scanning electron microscopy and energy-dispersive spectroscopy results confirmed that Bi(III) hydrolyzes on the surface of CuS to form a precipitate cover layer, which adsorbs onto the surface of CuS. This precipitate was confirmed by X-ray photoelectron spectroscopy analysis and thermodynamic calculations to be BiOCl. Fourier transform infrared analysis revealed that BiOCl reduces the recovery of CuS by hindering the adsorption of xanthate. Finally, the pre-treatment of the leaching residue with H2SO4 + NaCl solution can dissolve BiOCl precipitates on the surface of CuS, eliminate the influence of Bi(III), and result in efficient flotation recovery of CuS from leaching residue.
{"title":"Effect of Bi(III) on flotation of copper sulfide from leaching residue of copper smelting dust","authors":"Siyuan Wu, Chunhui Gao, Hang Chen, Tuoxiu Wu, Bao Guo, Rongdong Deng, Kaixi Jiang","doi":"10.1016/j.mineng.2024.109092","DOIUrl":"https://doi.org/10.1016/j.mineng.2024.109092","url":null,"abstract":"Flotation is a potential method for extracting residual copper sulfide (CuS) from the acid-leaching residue of copper smelting dust; however, the inhibitory impact of Bi(III) in the flotation pulp significantly hampers its practical application. In this study, we systematically investigated the inhibition mechanism of Bi(III) on CuS flotation and propose a method to prevent inhibition. Microflotation test results show that a pulp environment with pH 3 and a Bi(III) concentration greater than 1 × 10<ce:sup loc=\"post\">–2</ce:sup> mol/L significantly depresses the floatability of CuS. Scanning electron microscopy and energy-dispersive spectroscopy results confirmed that Bi(III) hydrolyzes on the surface of CuS to form a precipitate cover layer, which adsorbs onto the surface of CuS. This precipitate was confirmed by X-ray photoelectron spectroscopy analysis and thermodynamic calculations to be BiOCl. Fourier transform infrared analysis revealed that BiOCl reduces the recovery of CuS by hindering the adsorption of xanthate. Finally, the pre-treatment of the leaching residue with H<ce:inf loc=\"post\">2</ce:inf>SO<ce:inf loc=\"post\">4</ce:inf> + NaCl solution can dissolve BiOCl precipitates on the surface of CuS, eliminate the influence of Bi(III), and result in efficient flotation recovery of CuS from leaching residue.","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"22 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665616","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}
High gradient magnetic separation (HGMS) is a potential method of separating chalcopyrite from copper-arsenopyrite co-flotation concentrate. However, during the co-flotation process the addition of bleaching powder (ClO−), which has been a common depressant for arsenopyrite, deteriorates their separation selectivity in the subsequent HGMS process, and until today this effect of ClO− is unknown to people. Pulsating HGMS (PHGMS) technology was used to separate a pure chalcopyrite-arsenopyrite mixture containing 16.85 % Cu and 22.44 % As. It was found that when the concentration of ClO− was increased from 0 % to 10 %, the Cu recovery in magnetic chalcopyrite concentrate was increased from 79.07 % to 88.69 %, with its Cu grade decreased from 20.25 % to 17.65 %; and, the As recovery in the concentrate was significantly increased from 26.82 % to 65.50 %, with As grade increased from 9.92 % to 18.83 %. The X-ray photoelectron spectroscopy (XPS) and electrochemical analysis on the chalcopyrite concentrate revealed that ClO− preferentially oxidized the iron sulfides in arsenopyrite to iron oxides; and, the Crystal Field Theory (CFT) analysis revealed that the magnetic moment of Fe in arsenopyrite was increased from 0 to 5.92B.M after these Fe atoms reacted with ClO−, and the number of single electrons in Fe was increased from 0 to 5. As a result, the magnetic susceptibility of arsenopyrite was increased and more arsenopyrite particles were separated into chalcopyrite concentrate during the PHGMS process, deteriorating the separation selectivity of chalcopyrite from arsenopyrite.
{"title":"Effect of bleaching powder (ClO−) on pulsating HGMS of chalcopyrite from arsenopyrite","authors":"Pulin Dai, Luzheng Chen, Ruoyu Yang, Zixing Xue, Xiaowei Li, Tao Xiong, Jianwu Zeng","doi":"10.1016/j.mineng.2024.109102","DOIUrl":"https://doi.org/10.1016/j.mineng.2024.109102","url":null,"abstract":"High gradient magnetic separation (HGMS) is a potential method of separating chalcopyrite from copper-arsenopyrite co-flotation concentrate. However, during the co-flotation process the addition of bleaching powder (ClO<ce:sup loc=\"post\">−</ce:sup>), which has been a common depressant for arsenopyrite, deteriorates their separation selectivity in the subsequent HGMS process, and until today this effect of ClO<ce:sup loc=\"post\">−</ce:sup> is unknown to people. Pulsating HGMS (PHGMS) technology was used to separate a pure chalcopyrite-arsenopyrite mixture containing 16.85 % Cu and 22.44 % As. It was found that when the concentration of ClO<ce:sup loc=\"post\">−</ce:sup> was increased from 0 % to 10 %, the Cu recovery in magnetic chalcopyrite concentrate was increased from 79.07 % to 88.69 %, with its Cu grade decreased from 20.25 % to 17.65 %; and, the As recovery in the concentrate was significantly increased from 26.82 % to 65.50 %, with As grade increased from 9.92 % to 18.83 %. The X-ray photoelectron spectroscopy (XPS) and electrochemical analysis on the chalcopyrite concentrate revealed that ClO<ce:sup loc=\"post\">−</ce:sup> preferentially oxidized the iron sulfides in arsenopyrite to iron oxides; and, the Crystal Field Theory (CFT) analysis revealed that the magnetic moment of Fe in arsenopyrite was increased from 0 to 5.92B.M after these Fe atoms reacted with ClO<ce:sup loc=\"post\">−</ce:sup>, and the number of single electrons in Fe was increased from 0 to 5. As a result, the magnetic susceptibility of arsenopyrite was increased and more arsenopyrite particles were separated into chalcopyrite concentrate during the PHGMS process, deteriorating the separation selectivity of chalcopyrite from arsenopyrite.","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"178 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665608","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 : 2024-11-13DOI: 10.1016/j.mineng.2024.109090
Imtiaz Shah, Ghislain Bournival, François Guillard, Seher Ata
X-ray radiography presents a non-invasive and dynamic approach for examining multiphase flows, particularly in complex systems like flotation froths. While this technique has been applied successfully in various multiphase studies, such as granular flows and fluidised beds, its utilisation in understanding flotation froths is novel. This study aimed to investigate the behaviour of particles and bubbles within the froth phase using a unique flotation rig combined with an X-ray radiographic setup. Specifically, it sought to understand how the pulp-froth interface influences the entry of bubble clusters into the froth phase and to observe the journey of particles within the froth. The results provided tangible evidence supporting previously inferred phenomena. It was found that the interface between the pulp and froth acted as a barrier, impeding the entry of bubble clusters into the froth phase. However, what was particularly noteworthy about the study was its revelation of extraordinary dynamics in particle movement within the froth phase. These dynamics included the occurrence of reattachment and dropback at critical solid fractions, phenomena that were visually observed for the first time.
X 射线射线照相术是一种非侵入性的动态方法，可用于检查多相流，尤其是浮选泡沫等复杂系统中的多相流。虽然这项技术已成功应用于颗粒流动和流化床等各种多相研究，但将其用于了解浮选泡沫还是一项新技术。这项研究旨在利用独特的浮选设备和 X 射线放射成像装置来研究泡沫阶段中颗粒和气泡的行为。具体来说，它试图了解矿浆-浮渣界面如何影响气泡团进入浮渣相，并观察颗粒在浮渣中的移动过程。研究结果为之前的推断现象提供了具体证据。研究发现，纸浆和泡沫之间的界面起到了阻碍气泡团进入泡沫相的作用。然而，这项研究尤其值得注意的是，它揭示了颗粒在泡沫相中的非凡运动动态。这些动态包括在临界固体分数时发生的重新附着和回落，这是首次直观观察到的现象。
{"title":"Insights into froth phase dynamics: X-ray observations of particle behaviour","authors":"Imtiaz Shah, Ghislain Bournival, François Guillard, Seher Ata","doi":"10.1016/j.mineng.2024.109090","DOIUrl":"https://doi.org/10.1016/j.mineng.2024.109090","url":null,"abstract":"X-ray radiography presents a non-invasive and dynamic approach for examining multiphase flows, particularly in complex systems like flotation froths. While this technique has been applied successfully in various multiphase studies, such as granular flows and fluidised beds, its utilisation in understanding flotation froths is novel. This study aimed to investigate the behaviour of particles and bubbles within the froth phase using a unique flotation rig combined with an X-ray radiographic setup. Specifically, it sought to understand how the pulp-froth interface influences the entry of bubble clusters into the froth phase and to observe the journey of particles within the froth. The results provided tangible evidence supporting previously inferred phenomena. It was found that the interface between the pulp and froth acted as a barrier, impeding the entry of bubble clusters into the froth phase. However, what was particularly noteworthy about the study was its revelation of extraordinary dynamics in particle movement within the froth phase. These dynamics included the occurrence of reattachment and dropback at critical solid fractions, phenomena that were visually observed for the first time.","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"22 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665610","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 : 2024-11-12DOI: 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":"https://doi.org/10.1016/j.mineng.2024.109088","url":null,"abstract":"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 <ce:italic>N</ce:italic>,<ce:italic>N</ce:italic>-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.","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"18 1","pages":""},"PeriodicalIF":4.8,"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.
{"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":"https://doi.org/10.1016/j.mineng.2024.109065","url":null,"abstract":"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<ce:inf loc=\"post\">4</ce:inf>) and strontianite (SrCO<ce:inf loc=\"post\">3</ce:inf>). 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.","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"99 1","pages":""},"PeriodicalIF":4.8,"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":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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":"https://doi.org/10.1016/j.mineng.2024.109093","url":null,"abstract":"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 <ce:italic>R<ce:sup loc=\"post\">2</ce:sup></ce:italic> of 0.9063 with a processing time of 0.0035 seconds per image, while its competitors only reach the maximum <ce:italic>R<ce:sup loc=\"post\">2</ce:sup></ce:italic> 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 <ce:italic>MAPE</ce:italic> 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.","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"39 1","pages":""},"PeriodicalIF":4.8,"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}
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