Approximately 2.0-3.0 t of copper slag(CS) containing 35%-45% iron is generated for every ton of copper produced during the pyrometallurgical process from copper concentrate. Therefore, the recovery of iron from CS ut...Approximately 2.0-3.0 t of copper slag(CS) containing 35%-45% iron is generated for every ton of copper produced during the pyrometallurgical process from copper concentrate. Therefore, the recovery of iron from CS utilizes a valuable metal and alleviates the environmental stress caused by stockpile. In this paper, a new method has been developed to realize the enrichment of iron in CS through the selective removal of silica. The thermodynamic analyses and experimental results show that the iron in CS can be fully reduced into metallic iron by carbothermic reduction at 1473 K for 60 min. The silica was converted into free quartz solid solution(QSS) and cristobalite solid solution(CSS). QSS and CSS are readily soluble, whereas metallic iron is insoluble, in NaOH solution. Under optimal leaching conditions, a residue containing 87.32% iron is obtained by decreasing the silica content to 6.02% in the reduction roasted product. The zinc content in the residue is less than 0.05%. This study lays the foundation for the development of a new method to comprehensively extract silicon and iron in CS while avoiding the generation of secondary tailing.展开更多
Carbothermic reduction alumina in vacuum was conducted, and the products were analysed by means of XRD and gas chromatography. Thermodynamic analysis shows that in vacuum the initial carbothermic reduction reaction te...Carbothermic reduction alumina in vacuum was conducted, and the products were analysed by means of XRD and gas chromatography. Thermodynamic analysis shows that in vacuum the initial carbothermic reduction reaction temperature reduces compared with that under normal pressure, and the preferential order of products is Al404C, Al4C3, Al2OC, Al20 and A1. Experiment results show that the carbothermic reduction products of alumina are A1404C and A14C3, and neither A12OC, Al20 or Al was found. During the carbothermic reduction process, the reaction rate of Al203 and carbon decreases gradually with increasing time. Meanwhile, lower system pressure or higher temperature is beneficial to the carbothermic reduction of alumina process. A1404C is firstly formed in the carbothermic reaction, and then A14C3 is formed in lower system pressure or at higher temperature.展开更多
Sulfide solid electrolytes(S-SEs)are widely preferred for their high ionic conductivity and processability.However,the further development of S-SEs is hindered by the excessive price of its critical raw materials of L...Sulfide solid electrolytes(S-SEs)are widely preferred for their high ionic conductivity and processability.However,the further development of S-SEs is hindered by the excessive price of its critical raw materials of Li_(2)S.Herein,a low-cost and environmentally friendly method is proposed to synthesize Li_(2)S by the carbothermal reduction reaction of Li_(2)SO_(4)in one step,and the effects of various factors are also discussed.As a result,a purity of 99.67%is obtained over the self-prepared Li_(2)S.More importantly,the cost of the self-prepared Li_(2)S is only about 50$/kg,which is significantly lower than that of the commercial counterpart(10000−15000 dollar/kg).Moreover,the ionic conductivity of Li_(5.5)PS_(4.5)Cl_(1.5)prepared using self-prepared Li_(2)S as raw materials is 4.19 mS/cm at room temperature,which is a little higher than that of Li_(5.5)PS_(4.5)Cl_(1.5)using commercial Li_(2)S(4.05 mS/cm).And the all-solid-state lithium batteries(ASSLBs)with the as-prepared electrolytes could maintain a discharge capacity of 109.9 mA·h/g with an average coulombic efficiency(CE)of 98%after 100 cycles at 0.2 C,which is equivalent to that using commercial Li_(2)S,demonstrating that the preparation strategy of Li_(2)S proposed in this work is feasible.展开更多
To make sure the intermediate products of the carbothermic reduction of Al2O3 process, such as Al4CO4, Al2CO and Al4C3,and the interaction of AlCl, AlCl2, AlCl3 with Al4CO4, Al2CO and Al4C3, respectively, thermodynami...To make sure the intermediate products of the carbothermic reduction of Al2O3 process, such as Al4CO4, Al2CO and Al4C3,and the interaction of AlCl, AlCl2, AlCl3 with Al4CO4, Al2CO and Al4C3, respectively, thermodynamic analyses were used to study the chloride reaction production of them under the vacuum situation. The stable structures and electronic properties of AlCl, AlCl2 and AlCl3 adsorbed on Al4CO4, Al2CO and Al4C3 were calculated by first-principles calculations by the CASTEP module in the Materials Studio program. The results show that the AlCl3 and AlCl2 molecules have decomposed on the plane of Al4C3（001）, while there are no obvious decomposition of AlCl3 and AlCl2 on Al4CO4（001） and Al2CO（001） planes. The adsorption of AlCl on the Al4CO4（001）and Al2CO（001） planes is stronger than that on the Al4C3（001） plane. The interaction strength of AlCl3, as well as AlCl2, with Al4CO4,Al2CO and Al4C3 is in the sequence of Al4CO4Al2CO〉Al4C3.展开更多
基金Project(WUT:2019IVA096)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2019M662733)supported by China Postdoctoral Science FoundationProject(2018YFC1901502)supported by National Key Research and Development Program of China。
文摘Approximately 2.0-3.0 t of copper slag(CS) containing 35%-45% iron is generated for every ton of copper produced during the pyrometallurgical process from copper concentrate. Therefore, the recovery of iron from CS utilizes a valuable metal and alleviates the environmental stress caused by stockpile. In this paper, a new method has been developed to realize the enrichment of iron in CS through the selective removal of silica. The thermodynamic analyses and experimental results show that the iron in CS can be fully reduced into metallic iron by carbothermic reduction at 1473 K for 60 min. The silica was converted into free quartz solid solution(QSS) and cristobalite solid solution(CSS). QSS and CSS are readily soluble, whereas metallic iron is insoluble, in NaOH solution. Under optimal leaching conditions, a residue containing 87.32% iron is obtained by decreasing the silica content to 6.02% in the reduction roasted product. The zinc content in the residue is less than 0.05%. This study lays the foundation for the development of a new method to comprehensively extract silicon and iron in CS while avoiding the generation of secondary tailing.
基金Project(U0837604) supported by the Natural Science Foundation of Yunnan Province,ChinaProject(Jinchuan 201114) supported by the Pre Research Foundation of Jinchuan Group Ltd.,ChinaProject(2011148) supported by the Analysis and Testing Funds of Kunming University of Science and Technology,China
文摘Carbothermic reduction alumina in vacuum was conducted, and the products were analysed by means of XRD and gas chromatography. Thermodynamic analysis shows that in vacuum the initial carbothermic reduction reaction temperature reduces compared with that under normal pressure, and the preferential order of products is Al404C, Al4C3, Al2OC, Al20 and A1. Experiment results show that the carbothermic reduction products of alumina are A1404C and A14C3, and neither A12OC, Al20 or Al was found. During the carbothermic reduction process, the reaction rate of Al203 and carbon decreases gradually with increasing time. Meanwhile, lower system pressure or higher temperature is beneficial to the carbothermic reduction of alumina process. A1404C is firstly formed in the carbothermic reaction, and then A14C3 is formed in lower system pressure or at higher temperature.
基金Project(52374407)supported by the National Natural Science Foundation of China。
文摘Sulfide solid electrolytes(S-SEs)are widely preferred for their high ionic conductivity and processability.However,the further development of S-SEs is hindered by the excessive price of its critical raw materials of Li_(2)S.Herein,a low-cost and environmentally friendly method is proposed to synthesize Li_(2)S by the carbothermal reduction reaction of Li_(2)SO_(4)in one step,and the effects of various factors are also discussed.As a result,a purity of 99.67%is obtained over the self-prepared Li_(2)S.More importantly,the cost of the self-prepared Li_(2)S is only about 50$/kg,which is significantly lower than that of the commercial counterpart(10000−15000 dollar/kg).Moreover,the ionic conductivity of Li_(5.5)PS_(4.5)Cl_(1.5)prepared using self-prepared Li_(2)S as raw materials is 4.19 mS/cm at room temperature,which is a little higher than that of Li_(5.5)PS_(4.5)Cl_(1.5)using commercial Li_(2)S(4.05 mS/cm).And the all-solid-state lithium batteries(ASSLBs)with the as-prepared electrolytes could maintain a discharge capacity of 109.9 mA·h/g with an average coulombic efficiency(CE)of 98%after 100 cycles at 0.2 C,which is equivalent to that using commercial Li_(2)S,demonstrating that the preparation strategy of Li_(2)S proposed in this work is feasible.
基金Projects(51104078,51264023)supported by the National Natural Science Foundation of ChinaProject(2010CD022)supported by Yunnan Provincial Applied Basic Research Fund,China+2 种基金Project(IRT1250)supported by the Program for Innovative Research Team in University of Ministry of Education of ChinaProject(U1202271)supported by the National Natural Science Foundation of China-Yunnan United FundProject(KKZ3201252020)supported by Fund of Kunming University of Science and Technology for Talent Training,China
文摘To make sure the intermediate products of the carbothermic reduction of Al2O3 process, such as Al4CO4, Al2CO and Al4C3,and the interaction of AlCl, AlCl2, AlCl3 with Al4CO4, Al2CO and Al4C3, respectively, thermodynamic analyses were used to study the chloride reaction production of them under the vacuum situation. The stable structures and electronic properties of AlCl, AlCl2 and AlCl3 adsorbed on Al4CO4, Al2CO and Al4C3 were calculated by first-principles calculations by the CASTEP module in the Materials Studio program. The results show that the AlCl3 and AlCl2 molecules have decomposed on the plane of Al4C3（001）, while there are no obvious decomposition of AlCl3 and AlCl2 on Al4CO4（001） and Al2CO（001） planes. The adsorption of AlCl on the Al4CO4（001）and Al2CO（001） planes is stronger than that on the Al4C3（001） plane. The interaction strength of AlCl3, as well as AlCl2, with Al4CO4,Al2CO and Al4C3 is in the sequence of Al4CO4Al2CO〉Al4C3.
