Solid oxide membrane-assisted electrolytic reduction of solid Cr_(2)O_(3) to Cr in molten CaCl_(2) was performed using a sintered porous Cr_(2)O_(3) cathode paired with an yttria-stabilized zirconia(YSZ)tube anode con...Solid oxide membrane-assisted electrolytic reduction of solid Cr_(2)O_(3) to Cr in molten CaCl_(2) was performed using a sintered porous Cr_(2)O_(3) cathode paired with an yttria-stabilized zirconia(YSZ)tube anode containing carbon-saturated liquid copper alloy.Analyses of the reduction mechanism,ion migration behavior,and effects of cathode pellet porosity and particle size on the electrolysis products and reduction rate revealed that the cathode microstructure and electrolytic conditions were key factors influencing the electrolysis process.Optimal results were obtained when the cathode was characterized by high porosity and a small particle size because this combination of features contributed to ion migration.Good electrochemical activation was observed when cathode pellets prepared by 4 MPa molding followed by 2 h of sintering at 1150℃ were applied.The electrode reduction process(Cr^(3+)→Cr^(2+)→Cr)was promoted by high electrode voltages,and Cr metal was efficiently formed.The proposed method appears to be well suited for electrolytic Cr production because it does not require expensive pre-electrolysis techniques or generate harmful by-products.展开更多
Recovering iron and aluminum efficiently is the key route to utilize low-grade high-iron bauxite.Aiming to optimize the iron separating process and elevate both Fe and Al recovery ratio,three different Fe-Al recovery ...Recovering iron and aluminum efficiently is the key route to utilize low-grade high-iron bauxite.Aiming to optimize the iron separating process and elevate both Fe and Al recovery ratio,three different Fe-Al recovery processes with different magnetic roasting(R),Bayer leaching process(L)and magnetic separation(S)orders were investigated.The studied processes include bauxite leaching→red mud roasting→magnetic separation(L-R-S),bauxite roasting→magnetic separation→leaching(R-S-L)and bauxite roasting→leaching→magnetic separation(R-L-S).The iron recovery ratio,Fe2O3 content in iron concentration and the bauxite dissolution ratio of each process were investigated.Moreover,the optimizations of the leaching,roasting and magnetic separation conditions were studied.Results indicate that the R-S-L process should be an advisable order to recover both alumina and iron.In the three processes,the R-S-L route had the highest alumina dissolution ratio and iron recovery ratio,which was 86.20%and 69.58%,respectively,while the Fe2O3 content of the iron concentrate was 40.66%.展开更多
To improve the efficiency of iron recovery from steel slag and reduce the wear-and-tear on facilities, a new method was proposed by adding a secondary screen sizer to the magnetic separation process according to grain...To improve the efficiency of iron recovery from steel slag and reduce the wear-and-tear on facilities, a new method was proposed by adding a secondary screen sizer to the magnetic separation process according to grain size distribution of magnetic iron （M-Fe） in the slag. The final recycling efficiency was evaluated by calculating the percentage of recycled M-Fe to the maximum amount of M-Fe that could be recovered. Three types of slags, namely basic oxygen furnace slag, desul- furization slag, and iron ladle slag, were studied, and the results showed that the optimized re- covery efficieneies were 93.20%, 92. 48%, and 85.82% respectively, and the recycling efficien eies were improved by 9.58%, 7.11%, and 6.24% respectively. Furthermore, the abrasion between the mill equipment and the remaining slags was significantly reduced owing to the efficient recovery of larger M-Fe particles. In addition, the using amount of grinding balls was reduced by 0. 46 kg when every 1 t steel slag was processed.展开更多
基金Projects(U1812402,51774102,51574095,51664005)supported by the National Natural Science Foundation of ChinaProjects([2015]4005,[2017]5788,[2017]5626,KY(2015)334)supported by Talents of Guizhou Science and Technology Cooperation Platform,China。
基金the National Natural Science Foundation of China(Nos.51664005,51774102,U1812402,and 51804088)Talents of Guizhou Science and Technology Cooperation Platform(Platform Talent[2017]5626 and KY(2015)334)。
文摘Solid oxide membrane-assisted electrolytic reduction of solid Cr_(2)O_(3) to Cr in molten CaCl_(2) was performed using a sintered porous Cr_(2)O_(3) cathode paired with an yttria-stabilized zirconia(YSZ)tube anode containing carbon-saturated liquid copper alloy.Analyses of the reduction mechanism,ion migration behavior,and effects of cathode pellet porosity and particle size on the electrolysis products and reduction rate revealed that the cathode microstructure and electrolytic conditions were key factors influencing the electrolysis process.Optimal results were obtained when the cathode was characterized by high porosity and a small particle size because this combination of features contributed to ion migration.Good electrochemical activation was observed when cathode pellets prepared by 4 MPa molding followed by 2 h of sintering at 1150℃ were applied.The electrode reduction process(Cr^(3+)→Cr^(2+)→Cr)was promoted by high electrode voltages,and Cr metal was efficiently formed.The proposed method appears to be well suited for electrolytic Cr production because it does not require expensive pre-electrolysis techniques or generate harmful by-products.
基金The authors are appreciated for the financial support of the National Natural Science Foundation of China(51574095,51664005 and 51774102)Guizhou Alumina Production Technology and Technology Science and Technology Innovation Talent Team Project(Qian Ke He Talent Team Giant[2015]0.4005,Qian Ke He Platform Talent[2017]5788,the Cooperation Talent Group of Guizhou Department[2017]5626),Guizhou Metallurgical Resources Comprehensive Utilization Engineering Research Center Project(Qian Jiao He[2015]334)Guizhou University Postgraduate Innovation Fund(Research Institute of Technology 2016018).
文摘Recovering iron and aluminum efficiently is the key route to utilize low-grade high-iron bauxite.Aiming to optimize the iron separating process and elevate both Fe and Al recovery ratio,three different Fe-Al recovery processes with different magnetic roasting(R),Bayer leaching process(L)and magnetic separation(S)orders were investigated.The studied processes include bauxite leaching→red mud roasting→magnetic separation(L-R-S),bauxite roasting→magnetic separation→leaching(R-S-L)and bauxite roasting→leaching→magnetic separation(R-L-S).The iron recovery ratio,Fe2O3 content in iron concentration and the bauxite dissolution ratio of each process were investigated.Moreover,the optimizations of the leaching,roasting and magnetic separation conditions were studied.Results indicate that the R-S-L process should be an advisable order to recover both alumina and iron.In the three processes,the R-S-L route had the highest alumina dissolution ratio and iron recovery ratio,which was 86.20%and 69.58%,respectively,while the Fe2O3 content of the iron concentrate was 40.66%.
基金the funding of Chongqing Application and Development Project of China(cstc2014yykfB100007)
文摘To improve the efficiency of iron recovery from steel slag and reduce the wear-and-tear on facilities, a new method was proposed by adding a secondary screen sizer to the magnetic separation process according to grain size distribution of magnetic iron （M-Fe） in the slag. The final recycling efficiency was evaluated by calculating the percentage of recycled M-Fe to the maximum amount of M-Fe that could be recovered. Three types of slags, namely basic oxygen furnace slag, desul- furization slag, and iron ladle slag, were studied, and the results showed that the optimized re- covery efficieneies were 93.20%, 92. 48%, and 85.82% respectively, and the recycling efficien eies were improved by 9.58%, 7.11%, and 6.24% respectively. Furthermore, the abrasion between the mill equipment and the remaining slags was significantly reduced owing to the efficient recovery of larger M-Fe particles. In addition, the using amount of grinding balls was reduced by 0. 46 kg when every 1 t steel slag was processed.
