An efficient chlorination roasting process for recovering zinc(Zn)and lead(Pb)from copper smelting slag was proposed.Thermodynamic models were established,illustrating that Zn and Pb in copper smelting slag can be eff...An efficient chlorination roasting process for recovering zinc(Zn)and lead(Pb)from copper smelting slag was proposed.Thermodynamic models were established,illustrating that Zn and Pb in copper smelting slag can be efficiently recycled during the chlorination roasting process.By decreasing the partial pressure of the gaseous products,chlorination was promoted.The Box−Behnken design was applied to assessing the interactive effects of the process variables and optimizing the chlorination roasting process.CaCl_(2) dosage and roasting temperature and time were used as variables,and metal recovery efficiencies were used as responses.When the roasting temperature was 1172℃ with a CaCl_(2) addition amount of 30 wt.%and a roasting time of 100 min,the predicted optimal recovery efficiencies of Zn and Pb were 87.85%and 99.26%,respectively,and the results were validated by experiments under the same conditions.The residual Zn-and Pb-containing phases in the roasting slags were ZnFe_(2)O_(4),Zn_(2)SiO_(4),and PbS.展开更多
Nickel-based superalloy was treated with molten zinc for the selective extraction of nickel.The effects of heating temperature,heating time,and the mass ratio of zinc to superalloy on the extraction of metals in the s...Nickel-based superalloy was treated with molten zinc for the selective extraction of nickel.The effects of heating temperature,heating time,and the mass ratio of zinc to superalloy on the extraction of metals in the superalloy were investigated.An extraction rate of 95.2%for nickel,55.4%for iron and 30.4%for chromium,but low extraction rates of the refractory metals(titanium(Ti),molybdenum(Mo),and niobium(Nb))were obtained under the optimal conditions of the heating temperature of 850℃,the heating time of 4 h,and the zinc/superalloy mass ratio of 10:1.In the subsequent vacuum distillation process,the obtained nickel alloy contained nickel with a purity of 73.5 wt.%after zinc removal.Moreover,the recovered zinc after the distillation process had a purity of 99.9 wt.%.The results of the investigated process indicated the possibility of extracting nickel directly from nickel-based superalloy scraps.展开更多
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(Nos.51620105013,51904351)Innovation-Driven Project of Central South University,China(No.2020CX028)+1 种基金Natural Science Fund for Distinguished Young Scholar of Hunan Province,China(No.2019JJ20031)the National Key R&D Program of China(No.2019YFC1907400)。
文摘An efficient chlorination roasting process for recovering zinc(Zn)and lead(Pb)from copper smelting slag was proposed.Thermodynamic models were established,illustrating that Zn and Pb in copper smelting slag can be efficiently recycled during the chlorination roasting process.By decreasing the partial pressure of the gaseous products,chlorination was promoted.The Box−Behnken design was applied to assessing the interactive effects of the process variables and optimizing the chlorination roasting process.CaCl_(2) dosage and roasting temperature and time were used as variables,and metal recovery efficiencies were used as responses.When the roasting temperature was 1172℃ with a CaCl_(2) addition amount of 30 wt.%and a roasting time of 100 min,the predicted optimal recovery efficiencies of Zn and Pb were 87.85%and 99.26%,respectively,and the results were validated by experiments under the same conditions.The residual Zn-and Pb-containing phases in the roasting slags were ZnFe_(2)O_(4),Zn_(2)SiO_(4),and PbS.
基金financial supports from the National Natural Science Foundation of China(Nos.51922108,51874371,51904350)the Hunan Natural Science Foundation,China(No.2019JJ20031)the Hunan Key Research and Development Program,China(No.2019SK2061)。
文摘Nickel-based superalloy was treated with molten zinc for the selective extraction of nickel.The effects of heating temperature,heating time,and the mass ratio of zinc to superalloy on the extraction of metals in the superalloy were investigated.An extraction rate of 95.2%for nickel,55.4%for iron and 30.4%for chromium,but low extraction rates of the refractory metals(titanium(Ti),molybdenum(Mo),and niobium(Nb))were obtained under the optimal conditions of the heating temperature of 850℃,the heating time of 4 h,and the zinc/superalloy mass ratio of 10:1.In the subsequent vacuum distillation process,the obtained nickel alloy contained nickel with a purity of 73.5 wt.%after zinc removal.Moreover,the recovered zinc after the distillation process had a purity of 99.9 wt.%.The results of the investigated process indicated the possibility of extracting nickel directly from nickel-based superalloy scraps.
