【摘要】 研究通过用PbCO₃沉淀并用Na₂CO₃溶液浸出从钒沉淀溶液中分离和回收铬的循环冶金工艺。沉钒后液pH调至3.0后,按Pb/Cr摩尔比2.5加入PbCO₃,在30°C搅拌180 min,铬浓度从2.360 g/L降到0.001 g/L。过滤后,沉铬富集渣用热Na₂CO₃溶液浸出得到含有Na₂CrO₄的浸出液和含有PbCO₃的浸出渣。沉铬富集渣按液固比10:1 m L/g加入到0.5 mol/L的Na₂CO₃溶液中,调pH到9.5,在70°C搅拌60min,铬的浸出率为96.43%。过滤后,浸出渣返回沉铬,浸出液循环浸出铬直至Na₂CrO₄接近饱和。最后,浸出液蒸发结晶后获得Na₂CrO₄·4H₂O产物。更多还原

【Abstract】 Cyclic metallurgical process for separation and recovery of Cr from vanadium precipitated solution by precipitation with PbCO₃ and leaching with Na₂CO₃ was investigated. The concentration of Cr residue in the solution decreases from 2.360 to 0.001 g/L by adding PbCO₃ into vanadium precipitated solution according to Pb/Cr molar ratio of 2.5, adjusting the pH to 3.0 and stirring for 180 min at 30 °C. Then, the precipitates were leached with hot Na₂CO₃ solution to obtain leaching solution containing Na₂CrO₄ and leaching residue containing PbCO₃. The leaching efficiency of Cr reaches 96.43% by adding the precipitates into 0.5 mol/L Na₂CO₃ solution with the mass ratio of liquid to solid（L/S） of 10:1 mL/g and stirring for 60 min under pH 9.5 at 70 °C. After filtration, leaching residue is reused in Cr precipitation and leaching solution is used to circularly leach the Cr precipitates until Na₂CrO₄ approaches the saturation. Finally, the product of Na₂CrO₄·4H₂O is obtained by evaporation and crystallization of leaching solution.更多还原