The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6. Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu ...The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6. Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu to As was 2：1 and pH value of the neutralized wastewater was adjusted to 8.0 by sodium hydroxide. The arsenious acid solution and red residue were produced after copper arsenite mixed with water according to the ratio of liquid to solid of 4：1 and copper arsenite was reduced by SO2 at 60℃ for 1 h. The white powder was gained after the arsenious acid solution was evaporated and cooled. Copper sulfate solution was obtained after the red residue was leached by H2SO4 solution under the action of air. The results show that red residue is Cu3（SO3）2·2H2O and the white powder is As2O3. The leaching rate of Cu reaches 99.00% when the leaching time is 1.5 h, molar ratio of H2SO4 to Cu is 1.70, H2SO4 concentration is 24% and the leaching temperature is 80 ℃. The direct recovery rate of copper sulfate is 79.11% and the content of CuSOa·5H2O is up to 98.33% in the product after evaporating and cooling the copper sulfate solution.展开更多
To recover metal from copper slags,a new process involving two steps of oxidative desulfurization followed by smelting reduction was proposed in which one hazardous waste(waste cathode carbon)was used to treat another...To recover metal from copper slags,a new process involving two steps of oxidative desulfurization followed by smelting reduction was proposed in which one hazardous waste(waste cathode carbon)was used to treat another(copper slags).The waste cathode carbon is used not only as a reducing agent but also as a fluxing agent to decrease slag melting point.Upon holding for 60 min in air atmosphere first and then smelting with 14.4 wt%waste cathode carbon and 25 wt%CaO for 180 min in high purity Ar atmosphere at 1450℃,the recovery rates of Cu and Fe reach 95.89%and 94.64%,respectively,and meanwhile greater than 90%of the fluoride from waste cathode carbon is transferred into the final slag as CaF_(2) and Ca_(2)Si_(2)F_(2)O_(7),which makes the content of soluble F in the slag meet the national emission standard.Besides,the sulphur content in the obtained Fe-Cu alloy is low to 0.03 wt%.展开更多
A new hydrometallurgical route for separation and recovery of Cu from Cu-As-bearing copper electrorefining black slime was developed. The proposed process comprised oxidation acid leaching of Cu-As-bearing slime and s...A new hydrometallurgical route for separation and recovery of Cu from Cu-As-bearing copper electrorefining black slime was developed. The proposed process comprised oxidation acid leaching of Cu-As-bearing slime and selective sulfide precipitation of Cu from the leachate. The effects of various process parameters on the leaching and precipitation of Cu and As were investigated. At the first stage, Cu extraction of 95.2% and As extraction of 97.6% were obtained at 80 ℃ after 4 h with initial H2 SO4 concentration of 1.0 mol/L and liquid-to-solid ratio of 10 mL/g. In addition, the leaching kinetics of Cu and As was successfully reproduced by the Avrami model, and the apparent activation energies were found to be 33.6 and 35.1 kJ/mol for the Cu and As leaching reaction, respectively, suggesting a combination of chemical reaction and diffusion control. During the selective sulfide precipitation, about 99.4% Cu was recovered as CuS, while only 0.1% As was precipitated under the optimal conditions using sulfide-to-copper ratio of 2.4:1, time of 1.5 h and temperature of 25 ℃.展开更多
文摘The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6. Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu to As was 2：1 and pH value of the neutralized wastewater was adjusted to 8.0 by sodium hydroxide. The arsenious acid solution and red residue were produced after copper arsenite mixed with water according to the ratio of liquid to solid of 4：1 and copper arsenite was reduced by SO2 at 60℃ for 1 h. The white powder was gained after the arsenious acid solution was evaporated and cooled. Copper sulfate solution was obtained after the red residue was leached by H2SO4 solution under the action of air. The results show that red residue is Cu3（SO3）2·2H2O and the white powder is As2O3. The leaching rate of Cu reaches 99.00% when the leaching time is 1.5 h, molar ratio of H2SO4 to Cu is 1.70, H2SO4 concentration is 24% and the leaching temperature is 80 ℃. The direct recovery rate of copper sulfate is 79.11% and the content of CuSOa·5H2O is up to 98.33% in the product after evaporating and cooling the copper sulfate solution.
基金Project(U1602272)supported by the National Natural Science Foundation of China。
文摘To recover metal from copper slags,a new process involving two steps of oxidative desulfurization followed by smelting reduction was proposed in which one hazardous waste(waste cathode carbon)was used to treat another(copper slags).The waste cathode carbon is used not only as a reducing agent but also as a fluxing agent to decrease slag melting point.Upon holding for 60 min in air atmosphere first and then smelting with 14.4 wt%waste cathode carbon and 25 wt%CaO for 180 min in high purity Ar atmosphere at 1450℃,the recovery rates of Cu and Fe reach 95.89%and 94.64%,respectively,and meanwhile greater than 90%of the fluoride from waste cathode carbon is transferred into the final slag as CaF_(2) and Ca_(2)Si_(2)F_(2)O_(7),which makes the content of soluble F in the slag meet the national emission standard.Besides,the sulphur content in the obtained Fe-Cu alloy is low to 0.03 wt%.
基金financial supports from the National Natural Science Foundation of China (51634010,51904354)the National Science Fund for Distinguished Young Scholars of China (51825403)+1 种基金the National Key R&D Program of China (2018YFC1900306,2019YFC1907405)Key Research and Development Program of Hunan Province,China (2019SK2291)。
文摘A new hydrometallurgical route for separation and recovery of Cu from Cu-As-bearing copper electrorefining black slime was developed. The proposed process comprised oxidation acid leaching of Cu-As-bearing slime and selective sulfide precipitation of Cu from the leachate. The effects of various process parameters on the leaching and precipitation of Cu and As were investigated. At the first stage, Cu extraction of 95.2% and As extraction of 97.6% were obtained at 80 ℃ after 4 h with initial H2 SO4 concentration of 1.0 mol/L and liquid-to-solid ratio of 10 mL/g. In addition, the leaching kinetics of Cu and As was successfully reproduced by the Avrami model, and the apparent activation energies were found to be 33.6 and 35.1 kJ/mol for the Cu and As leaching reaction, respectively, suggesting a combination of chemical reaction and diffusion control. During the selective sulfide precipitation, about 99.4% Cu was recovered as CuS, while only 0.1% As was precipitated under the optimal conditions using sulfide-to-copper ratio of 2.4:1, time of 1.5 h and temperature of 25 ℃.
