A direct alkaline leaching process was proposed to extract molybdenum and lead from low-grade wulfenite ore containing 2.87%Mo and 9.39%Pb.The results show that increasing temperature and alkali concentration enhances...A direct alkaline leaching process was proposed to extract molybdenum and lead from low-grade wulfenite ore containing 2.87%Mo and 9.39%Pb.The results show that increasing temperature and alkali concentration enhances the extraction of Mo and Pb,and more than 99.7%of Mo and 64.6%of Pb are extracted under conditions of 75℃,L/S of 2:1,leaching time of 1.0 h,initial NaOH concentration of 80 g/L and stirring speed of 100 r/min.The alkaline leaching of molybdenum follows a chemical reaction control mechanism with activation energy of 46.3 kJ/mol.Lead in the residue is recovered by hydrochloric acid leaching.99.8%of lead is leached under the conditions of 80℃,[MnO2]/[Pb]molar ratio of 1.3:1,sodium chloride concentration of 40 g/L,and hydrochloric acid concentration of 3 mol/L,and a product of crystallized PbCl2 with purity higher than 99.5%is obtained after cooling.展开更多
The desulfurization and resulfurization of slag containing oxides of vanadium and titanium(CaO–SiO_(2)–MgO–Al_(2)O_(3)–V_(2)O_(3)–TiO_(2)–FeO)in the pretreatment of semi-steel desulfurization at 1623 K were inve...The desulfurization and resulfurization of slag containing oxides of vanadium and titanium(CaO–SiO_(2)–MgO–Al_(2)O_(3)–V_(2)O_(3)–TiO_(2)–FeO)in the pretreatment of semi-steel desulfurization at 1623 K were investigated.Based on the ionic structure theory of slag,it could be concluded that V_(2)O_(3) and TiO_(2) combined with(O_(2)–)to form complex anions including VO_(3)^(3–),TiO_(4)^(4–),etc.,which reduced the activity of(O_(2)–)and decreased the sulfur partition ratio(LS).And FeO enhanced the activity of[O]at the slag–metal interface,which decreased the desulfurization capacity of the slag.Compared to the binary basicity,the presented basicity expression containing V_(2)O_(3) and TiO_(2) described the relationship between LS and basicity more accurately.Considering the problems of dilute slag,a large amount of residual slag and much resulfurization in the slagging-off process after pretreatment,the effect of CaO+C-based slag modifier on the resulfurization,melting point and viscosity of the desulfurization slag was investigated.It was proposed that adding 5%–10%of the slag modifier to the desulfurization slag after desulfurization decreased the resulfurization effectively.And the added modifier adjusted the slag viscosity well,which helped to reduce iron loss and residual slag.展开更多
基金Project(2012BAB10B06) supported by the National Science and Technology Pillar Program of ChinaProject(51434001) supported by the National Natural Science Foundation of China
文摘A direct alkaline leaching process was proposed to extract molybdenum and lead from low-grade wulfenite ore containing 2.87%Mo and 9.39%Pb.The results show that increasing temperature and alkali concentration enhances the extraction of Mo and Pb,and more than 99.7%of Mo and 64.6%of Pb are extracted under conditions of 75℃,L/S of 2:1,leaching time of 1.0 h,initial NaOH concentration of 80 g/L and stirring speed of 100 r/min.The alkaline leaching of molybdenum follows a chemical reaction control mechanism with activation energy of 46.3 kJ/mol.Lead in the residue is recovered by hydrochloric acid leaching.99.8%of lead is leached under the conditions of 80℃,[MnO2]/[Pb]molar ratio of 1.3:1,sodium chloride concentration of 40 g/L,and hydrochloric acid concentration of 3 mol/L,and a product of crystallized PbCl2 with purity higher than 99.5%is obtained after cooling.
文摘The desulfurization and resulfurization of slag containing oxides of vanadium and titanium(CaO–SiO_(2)–MgO–Al_(2)O_(3)–V_(2)O_(3)–TiO_(2)–FeO)in the pretreatment of semi-steel desulfurization at 1623 K were investigated.Based on the ionic structure theory of slag,it could be concluded that V_(2)O_(3) and TiO_(2) combined with(O_(2)–)to form complex anions including VO_(3)^(3–),TiO_(4)^(4–),etc.,which reduced the activity of(O_(2)–)and decreased the sulfur partition ratio(LS).And FeO enhanced the activity of[O]at the slag–metal interface,which decreased the desulfurization capacity of the slag.Compared to the binary basicity,the presented basicity expression containing V_(2)O_(3) and TiO_(2) described the relationship between LS and basicity more accurately.Considering the problems of dilute slag,a large amount of residual slag and much resulfurization in the slagging-off process after pretreatment,the effect of CaO+C-based slag modifier on the resulfurization,melting point and viscosity of the desulfurization slag was investigated.It was proposed that adding 5%–10%of the slag modifier to the desulfurization slag after desulfurization decreased the resulfurization effectively.And the added modifier adjusted the slag viscosity well,which helped to reduce iron loss and residual slag.
