In this work, iminodiacetic acid-functionalized graphene oxide (IDA@GO) is prepared and used as a nanocollector for enhancing and selectively recovering Pb(II) from a strongly acidic waste electrolyte via ion flotation. IDA@GO is characterized by Fourier transform infrared spectroscopy, zeta potential measurements and atomic force microscopy. The effects of pH, reaction time, cetyl trimethyl ammonium bromide (CTAB) dosage and aeration rate on the Pb(II) concentration and turbidity of the residual solution are examined systematically. The experimental results show that the adsorption capacity of Pb(II) on IDA@GO can reach 91.21 mg/g at pH 2. After froth flotation, the turbidity of the treated solution decreased to 0.55 NTU under the optimal CTAB dosage and aeration rate. In addition, as compared with GO, the relative selectivity coefficients of IDA@GO are up to 1.304, 1.471, 1.807 and 1.509 for Co(II), Ni(II), Zn(II) and Cd(II), respectively, thereby exhibiting better selectivity performance. Moreover, IDA@GO can be reused as a nanocollector in ion flotation and exhibits ideal regeneration performance. In addition, the recovery mechanism is found to proceed through Pb(II) adsorbing on IDA@GO by electrostatic attraction, ion exchange and surface complexation, with the addition of CTAB improving the hydrophobicity of Pb(II)-loaded IDA@GO flocs, thus achieving the recovery of Pb(II) via froth flotation.
{"title":"Selective recovery of Pb(II) from a waste electrolyte via ion flotation with iminodiacetic acid-functionalized graphene oxide as a nanocollector","authors":"Luping Chang, W. Peng, Yijun Cao, Yihe Miao, Guixia Fan, Yukun Huang, Xiangyu Song, Xianggen Chen","doi":"10.20517/mmm.2022.03","DOIUrl":"https://doi.org/10.20517/mmm.2022.03","url":null,"abstract":"In this work, iminodiacetic acid-functionalized graphene oxide (IDA@GO) is prepared and used as a nanocollector for enhancing and selectively recovering Pb(II) from a strongly acidic waste electrolyte via ion flotation. IDA@GO is characterized by Fourier transform infrared spectroscopy, zeta potential measurements and atomic force microscopy. The effects of pH, reaction time, cetyl trimethyl ammonium bromide (CTAB) dosage and aeration rate on the Pb(II) concentration and turbidity of the residual solution are examined systematically. The experimental results show that the adsorption capacity of Pb(II) on IDA@GO can reach 91.21 mg/g at pH 2. After froth flotation, the turbidity of the treated solution decreased to 0.55 NTU under the optimal CTAB dosage and aeration rate. In addition, as compared with GO, the relative selectivity coefficients of IDA@GO are up to 1.304, 1.471, 1.807 and 1.509 for Co(II), Ni(II), Zn(II) and Cd(II), respectively, thereby exhibiting better selectivity performance. Moreover, IDA@GO can be reused as a nanocollector in ion flotation and exhibits ideal regeneration performance. In addition, the recovery mechanism is found to proceed through Pb(II) adsorbing on IDA@GO by electrostatic attraction, ion exchange and surface complexation, with the addition of CTAB improving the hydrophobicity of Pb(II)-loaded IDA@GO flocs, thus achieving the recovery of Pb(II) via froth flotation.","PeriodicalId":319570,"journal":{"name":"Minerals and Mineral Materials","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123466591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Porous carbons have gained great attention for applications in lithium-sulfur (Li-S) batteries. However, achieving high specific surface area, hierarchical porosity, and abundant heteroatom-doping with facile approaches is still challenging. Herein, nitrogen, sulfur dual-doped hierarchical porous carbons (PBF@N@S) are obtained via a simple and sustainable activation process of cotton fibers. The as-prepared PBF@N@S exhibits a hierarchically interconnected network porous structure and large specific surface area. Meanwhile, abundant nitrogen, sulfur atoms are simultaneously doped in the carbons. These characteristics make the carbon favorable for hosting sulfur. The PBF@N@S sample with 50 wt% sulfur content (PBF@N@S-S-50%) delivers a high initial capacity with excellent cycling performance. Such high performance suggests that the PBF@N@S-S could be a promising cathode material for Li-S batteries.
多孔碳在锂硫电池中的应用受到了广泛的关注。然而,用简单的方法实现高比表面积、分层孔隙度和丰富的杂原子掺杂仍然是一个挑战。本文通过棉纤维的简单可持续活化工艺制备了氮、硫双掺杂分层多孔碳(PBF@N@S)。制备的PBF@N@S具有分层互连的网状多孔结构和较大的比表面积。同时,丰富的氮、硫原子同时掺杂在碳中。这些特性使碳有利于含硫。含有50 wt%硫含量(PBF@N@S- s -50%)的PBF@N@S样品具有高初始容量和优异的循环性能。如此高的性能表明PBF@N@S-S有可能成为锂硫电池的正极材料。
{"title":"Nitrogen sulfur dual-doped porous biochar fibers for high performance lithium-sulfur battery","authors":"Xuefeng Li, Kaige Sun","doi":"10.20517/mmm.2023.06","DOIUrl":"https://doi.org/10.20517/mmm.2023.06","url":null,"abstract":"Porous carbons have gained great attention for applications in lithium-sulfur (Li-S) batteries. However, achieving high specific surface area, hierarchical porosity, and abundant heteroatom-doping with facile approaches is still challenging. Herein, nitrogen, sulfur dual-doped hierarchical porous carbons (PBF@N@S) are obtained via a simple and sustainable activation process of cotton fibers. The as-prepared PBF@N@S exhibits a hierarchically interconnected network porous structure and large specific surface area. Meanwhile, abundant nitrogen, sulfur atoms are simultaneously doped in the carbons. These characteristics make the carbon favorable for hosting sulfur. The PBF@N@S sample with 50 wt% sulfur content (PBF@N@S-S-50%) delivers a high initial capacity with excellent cycling performance. Such high performance suggests that the PBF@N@S-S could be a promising cathode material for Li-S batteries.","PeriodicalId":319570,"journal":{"name":"Minerals and Mineral Materials","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128529672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Min, Lu-Zhuang Wang, Jun Chen, Chunfu Liu, Bao Ren, Lianfeng Zhang, Yi-Sheng Zhu
Clay minerals, which are prevalent gangue minerals, are found in tailings and beneficiation effluent after the extraction of valuable minerals. The surface of clay mineral particles is easy to hydrate, which makes it the main factor restricting tailings separation and wastewater treatment. However, the microscopic mechanism of clay mineral particle surface hydration is not yet systematic. In recent years, with the development of molecular simulation theory and the improvement of computational efficiency, density functional theory (DFT) and molecular dynamics (MD) have gradually become a powerful tool for studying the surface hydration of clay mineral particles, which provides new insight into the interaction between the crystal structures of clay minerals and the interfacial interaction in surface hydration of clay mineral particles at the molecular or atomic levels. This article first reviews the basic theory of DFT and MD, then reviews the research progress on clay mineral surface hydration. From the perspective of molecular simulation, a comprehensive discussion of the clay mineral phase structure, the establishment of the supercell surface model, the clay-water interface interaction and the limitations of molecular simulation was conducted. Water molecules can adsorb with different mineral surfaces in slime water through hydrogen bond, which is the basis of surface hydration mechanism. The hydration layer is composed of three water layers with different densities, with a thickness of about 8-10 Å. Water and ions form hydrate cations, which are adsorbed on the surface of clay minerals, change the structure of water layer on the surface of minerals. This article ends with a brief discussion of conclusions and perspectives.
{"title":"Molecular simulation in surface hydration of clay minerals: a review of theory and applications","authors":"F. Min, Lu-Zhuang Wang, Jun Chen, Chunfu Liu, Bao Ren, Lianfeng Zhang, Yi-Sheng Zhu","doi":"10.20517/mmm.2022.01","DOIUrl":"https://doi.org/10.20517/mmm.2022.01","url":null,"abstract":"Clay minerals, which are prevalent gangue minerals, are found in tailings and beneficiation effluent after the extraction of valuable minerals. The surface of clay mineral particles is easy to hydrate, which makes it the main factor restricting tailings separation and wastewater treatment. However, the microscopic mechanism of clay mineral particle surface hydration is not yet systematic. In recent years, with the development of molecular simulation theory and the improvement of computational efficiency, density functional theory (DFT) and molecular dynamics (MD) have gradually become a powerful tool for studying the surface hydration of clay mineral particles, which provides new insight into the interaction between the crystal structures of clay minerals and the interfacial interaction in surface hydration of clay mineral particles at the molecular or atomic levels. This article first reviews the basic theory of DFT and MD, then reviews the research progress on clay mineral surface hydration. From the perspective of molecular simulation, a comprehensive discussion of the clay mineral phase structure, the establishment of the supercell surface model, the clay-water interface interaction and the limitations of molecular simulation was conducted. Water molecules can adsorb with different mineral surfaces in slime water through hydrogen bond, which is the basis of surface hydration mechanism. The hydration layer is composed of three water layers with different densities, with a thickness of about 8-10 Å. Water and ions form hydrate cations, which are adsorbed on the surface of clay minerals, change the structure of water layer on the surface of minerals. This article ends with a brief discussion of conclusions and perspectives.","PeriodicalId":319570,"journal":{"name":"Minerals and Mineral Materials","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116429455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Research subjects suggested to young scientists in mineral processing to tackle future challenges of mining and minerals processing","authors":"Shaoxian Song","doi":"10.20517/mmm.2022.08","DOIUrl":"https://doi.org/10.20517/mmm.2022.08","url":null,"abstract":"","PeriodicalId":319570,"journal":{"name":"Minerals and Mineral Materials","volume":"72 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125179601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The recovery of rare earth elements (REEs) from the Western Kentucky No. 13 and Fire Clay coal wastes was enhanced by alkali pretreatment with concentrated NaOH solutions. The enhancements in the recovery of light REEs (LREEs) are more significant than those of heavy REEs (HREEs). For example, after treating with 5 M NaOH at 90 °C, the recovery of LREEs from the Western Kentucky No. 13 coal waste increased from 26% to 71%, while the recovery of HREEs only increased from 29% to 41%. Based on mineralogical studies through scanning electron microscopy-energy dispersive X-ray spectroscopy and X-ray diffraction analyses, two mechanisms were proposed to explain the positive effect of alkali pretreatment: (1) decomposition of rare earth minerals (primarily crandallite-group minerals) during the alkali pretreatment, and (2) liberation of encapsulated REE-bearing particles due to the enhanced dissolution of clay minerals. The more significant enhancements in the recovery of LREEs were explained by the fact that the REEs comprised in the crandallite-group minerals were mainly LREEs. Compared with zircon, monazite, and xenotime, alkali pretreatment with 5 M NaOH led to a more significant decomposition of crandallite-group minerals. In order to further increase the recovery of REEs, particularly HREEs, harsher alkali treatment conditions are required.
采用浓NaOH溶液进行碱预处理,提高了西部肯塔基州13号煤和火煤矸石中稀土元素的回收率。轻稀土(lree)的回收率比重稀土(hree)的提高更为显著。例如,在90℃条件下用5 M NaOH处理后,西肯塔基州13号煤矸石中lree的回收率从26%提高到71%,而hree的回收率仅从29%提高到41%。通过扫描电镜、x射线能谱和x射线衍射分析等矿物学研究,提出碱预处理的积极作用机理:(1)碱预处理过程中稀土矿物(主要是辉钼矿群矿物)的分解作用;(2)粘土矿物的溶解作用增强,使包裹的稀土颗粒析出。重稀土元素回收率显著提高的原因是辉长岩群矿物中稀土元素主要为轻稀土元素。与锆石、独居石和xenotime相比,5 M NaOH碱预处理对辉长石群矿物的分解作用更为显著。为了进一步提高稀土,特别是重稀土的回收率,需要更苛刻的碱处理条件。
{"title":"Alkali pretreatment effects on acid leaching recovery of rare earth elements from coal waste of the Western Kentucky No. 13 and Fire Clay seams","authors":"Qi Li, Bin Ji, Zhong Xiao, Wencai Zhang","doi":"10.20517/mmm.2022.05","DOIUrl":"https://doi.org/10.20517/mmm.2022.05","url":null,"abstract":"The recovery of rare earth elements (REEs) from the Western Kentucky No. 13 and Fire Clay coal wastes was enhanced by alkali pretreatment with concentrated NaOH solutions. The enhancements in the recovery of light REEs (LREEs) are more significant than those of heavy REEs (HREEs). For example, after treating with 5 M NaOH at 90 °C, the recovery of LREEs from the Western Kentucky No. 13 coal waste increased from 26% to 71%, while the recovery of HREEs only increased from 29% to 41%. Based on mineralogical studies through scanning electron microscopy-energy dispersive X-ray spectroscopy and X-ray diffraction analyses, two mechanisms were proposed to explain the positive effect of alkali pretreatment: (1) decomposition of rare earth minerals (primarily crandallite-group minerals) during the alkali pretreatment, and (2) liberation of encapsulated REE-bearing particles due to the enhanced dissolution of clay minerals. The more significant enhancements in the recovery of LREEs were explained by the fact that the REEs comprised in the crandallite-group minerals were mainly LREEs. Compared with zircon, monazite, and xenotime, alkali pretreatment with 5 M NaOH led to a more significant decomposition of crandallite-group minerals. In order to further increase the recovery of REEs, particularly HREEs, harsher alkali treatment conditions are required.","PeriodicalId":319570,"journal":{"name":"Minerals and Mineral Materials","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125955576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}