Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and ...Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.展开更多
Roasting experiments were carried out with pure reagents as raw materials.The self-sintering behaviors of molybdenite(MoS_(2))during oxidation were investigated by thermodynamic calculation,XRD,SEM-EDS and high-temper...Roasting experiments were carried out with pure reagents as raw materials.The self-sintering behaviors of molybdenite(MoS_(2))during oxidation were investigated by thermodynamic calculation,XRD,SEM-EDS and high-temperature in situ analysis.The results indicate that the desulfurization efficiency of MoS_(2) pellet decreases with the increase of roasting temperature from 600 to 700℃,owing to the expansion of sintered area.At the very beginning of roasting,sintered layer can be rapidly formed and cover the pellet surface on the windward side,and meanwhile,MoO_(2)and Mo_(4)O_(11) intensively appear and constitute the sintered layer together with MoO_(3).Moreover,it is proven that MoO_(3)-rich products containing low-valence molybdenum oxides have low melting points,thus easy to be melted during the occurrence of exothermic reaction between MoS_(2) and O_(2),which leads to the sintering of materials.展开更多
Pilot experiments on Na;SO;-roasting of V-Ti magnetite(VTM) concentrate pellets were performed to activate vanadium with simulated grate-kiln machines. Combined with thermodynamic calculation, X-ray diffraction(XRD), ...Pilot experiments on Na;SO;-roasting of V-Ti magnetite(VTM) concentrate pellets were performed to activate vanadium with simulated grate-kiln machines. Combined with thermodynamic calculation, X-ray diffraction(XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy(SEM-EDS), and inductively coupled plasma-atomic emission spectrometry(ICP-AES) analyses, process parameters of pellet making were optimized, and the enhancement of vanadium oxidation and conversion was realized. The results show that, in balling stage, adding Na;SO;can promote the thermal decrepitation resistance of green pellets;in the drying stage, higher wind temperature can improve the dispersion of sodium salt in pellets;in preheating stage, using O;-rich hot gas can promote more thorough oxidation of vanadium;in roasting stage, the effect of vanadium conversion to sodium vanadate is better when the liquid amount is 15.5%-22.5%. Based on the above measures, the vanadium conversion rate achieved in the roasted pellets is 85.6%, proving the feasibility of vanadium recovery using an existing pellet production line.展开更多
1 Introduction The regeneration and revitalization of historic conservation areas is not only of significant importance for the transformation of urban spaces but also has become a widely discussed topic in recent urb...1 Introduction The regeneration and revitalization of historic conservation areas is not only of significant importance for the transformation of urban spaces but also has become a widely discussed topic in recent urban renewal efforts.The Yongqing Fang,sitting in the Enning Road 1 Introduction The regeneration and revitalization of historic conservation areas is not only of significant importance for the transformation of urban spaces but also has become a widely discussed topic in recent urban renewal efforts.The Yongqing Fang,sitting in the Enning Road Historic Conservation Area in Guangzhou,China is renowned as“the most beautiful old-style street in Guangzhou.”Through its staged redevelopment since 2016,Yongqing Fang has turned into an attractive destination with distinctive Lingnan(Cantonese)characteristics,providing places for specialty dining,creative industries,cultural performances,recreational and cultural experiences,etc.This renewal project has also stimulated the coordinated development of the surrounding areas.展开更多
Selective separation of dissolved tungsten and vanadium is of great significance for the utilization of the secondary resources of these elements.In this work,selective removal of vanadium from tungstate solutions via...Selective separation of dissolved tungsten and vanadium is of great significance for the utilization of the secondary resources of these elements.In this work,selective removal of vanadium from tungstate solutions via microbubble floating-extraction was systematically investigated.The results indicated that vanadium can be more easily mineralized over tungsten from tungstate solutions using methyl trioctyl ammonium chloride as mineralization reagent under weak alkaline conditions.Owing to the higher bubble and interface mass transfer rates,high-efficiency enrichment and deep separation of vanadium could be achieved easily.Additionally,the deep recovery of tungsten and vanadium from the floated organic phase could be easily realized using a mixed solution of sodium hydroxide and sodium chloride as stripping agents.The separation mechanism mainly included the formation of hydrophobic complexes,their attachment on the surface of rising bubbles,and their mass transfer at the oil–water interface.Under the optimal conditions,the removal efficiency of vanadium reached 98.5%with tungsten loss below 8%after two-stage microbubble floating-extraction.Therefore,the microbubble floating-extraction could be an efficient approach for separating selectively vanadium from tungstate solutions,exhibiting outstanding advantages of high separation efficiency and low consumption of organic solvents.展开更多
基金financially supported by the Original Exploration Project of the National Natural Science Foundation of China(No.52150079)the National Natural Science Foundation of China(Nos.U22A20130,U2004215,and 51974280)+1 种基金the Natural Science Foundation of Henan Province of China(No.232300421196)the Project of Zhongyuan Critical Metals Laboratory of China(Nos.GJJSGFYQ202304,GJJSGFJQ202306,GJJSGFYQ202323,GJJSGFYQ202308,and GJJSGFYQ202307)。
文摘Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.
基金financially supported by the Basic Science Center Program of the National Natural Science Foundation of China(No.72088101)the General Program of the National Natural Science Foundation of China(No.51874355)the Special Funding of China Postdoctoral Science Foundation(No.2020T130730)。
文摘Roasting experiments were carried out with pure reagents as raw materials.The self-sintering behaviors of molybdenite(MoS_(2))during oxidation were investigated by thermodynamic calculation,XRD,SEM-EDS and high-temperature in situ analysis.The results indicate that the desulfurization efficiency of MoS_(2) pellet decreases with the increase of roasting temperature from 600 to 700℃,owing to the expansion of sintered area.At the very beginning of roasting,sintered layer can be rapidly formed and cover the pellet surface on the windward side,and meanwhile,MoO_(2)and Mo_(4)O_(11) intensively appear and constitute the sintered layer together with MoO_(3).Moreover,it is proven that MoO_(3)-rich products containing low-valence molybdenum oxides have low melting points,thus easy to be melted during the occurrence of exothermic reaction between MoS_(2) and O_(2),which leads to the sintering of materials.
基金financially supported by the Science and Technology Innovation Program of Hunan Province, China (No. 2021RC2003)the National Natural Science Foundation of China (No. 72088101)China Postdoctoral Science Foundation (No. 2021TQ0370)。
文摘Pilot experiments on Na;SO;-roasting of V-Ti magnetite(VTM) concentrate pellets were performed to activate vanadium with simulated grate-kiln machines. Combined with thermodynamic calculation, X-ray diffraction(XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy(SEM-EDS), and inductively coupled plasma-atomic emission spectrometry(ICP-AES) analyses, process parameters of pellet making were optimized, and the enhancement of vanadium oxidation and conversion was realized. The results show that, in balling stage, adding Na;SO;can promote the thermal decrepitation resistance of green pellets;in the drying stage, higher wind temperature can improve the dispersion of sodium salt in pellets;in preheating stage, using O;-rich hot gas can promote more thorough oxidation of vanadium;in roasting stage, the effect of vanadium conversion to sodium vanadate is better when the liquid amount is 15.5%-22.5%. Based on the above measures, the vanadium conversion rate achieved in the roasted pellets is 85.6%, proving the feasibility of vanadium recovery using an existing pellet production line.
文摘1 Introduction The regeneration and revitalization of historic conservation areas is not only of significant importance for the transformation of urban spaces but also has become a widely discussed topic in recent urban renewal efforts.The Yongqing Fang,sitting in the Enning Road 1 Introduction The regeneration and revitalization of historic conservation areas is not only of significant importance for the transformation of urban spaces but also has become a widely discussed topic in recent urban renewal efforts.The Yongqing Fang,sitting in the Enning Road Historic Conservation Area in Guangzhou,China is renowned as“the most beautiful old-style street in Guangzhou.”Through its staged redevelopment since 2016,Yongqing Fang has turned into an attractive destination with distinctive Lingnan(Cantonese)characteristics,providing places for specialty dining,creative industries,cultural performances,recreational and cultural experiences,etc.This renewal project has also stimulated the coordinated development of the surrounding areas.
基金supported by the Original Exploration Project of China(Grant No.52150079)the National Natural Science Foundation of China(Grant Nos.U2004215,51974280,51774252)the Educational Commission Fund of Henan Province of China(Grant Nos.20HASTIT012,18A450001,17A450001).
文摘Selective separation of dissolved tungsten and vanadium is of great significance for the utilization of the secondary resources of these elements.In this work,selective removal of vanadium from tungstate solutions via microbubble floating-extraction was systematically investigated.The results indicated that vanadium can be more easily mineralized over tungsten from tungstate solutions using methyl trioctyl ammonium chloride as mineralization reagent under weak alkaline conditions.Owing to the higher bubble and interface mass transfer rates,high-efficiency enrichment and deep separation of vanadium could be achieved easily.Additionally,the deep recovery of tungsten and vanadium from the floated organic phase could be easily realized using a mixed solution of sodium hydroxide and sodium chloride as stripping agents.The separation mechanism mainly included the formation of hydrophobic complexes,their attachment on the surface of rising bubbles,and their mass transfer at the oil–water interface.Under the optimal conditions,the removal efficiency of vanadium reached 98.5%with tungsten loss below 8%after two-stage microbubble floating-extraction.Therefore,the microbubble floating-extraction could be an efficient approach for separating selectively vanadium from tungstate solutions,exhibiting outstanding advantages of high separation efficiency and low consumption of organic solvents.
