铜浸出液氧化-水解除铁及回收铜的试验研究

针对Fe和Cu含量分别为2.158 g/L和0.730 g/L的含铜硫酸渣浸出液,采用氧化-中和水解除铁-硫化沉淀法回收其中的铜。对比了碳酸钠与石灰乳两种水解沉淀剂的除铁效果以及硫化钠与硫代硫酸钠两种沉铜剂的效果。最佳除铁条件为: 以碳酸钠为除铁水解沉淀剂、H₂O₂和铁离子摩尔比1.5、水解pH值4.0、水解温度85 ℃、水解时间3 h,最佳沉铜条件为: 硫化钠作为沉铜剂(用量为除铁后液中铜离子的等摩尔数)、沉淀pH值4.0、沉淀温度85 ℃、沉淀时间2 h。最佳工艺条件下,浸出液综合除铁率为92.98%、铜综合回收率为90.34%,沉淀得到铜品位为61.65%的硫化铜渣,可作为冶炼产品直接出售。

Experimental Study on Oxidation and Hydrolysis Process for Removing Iron and Recovering Copper from Copper Lixivium

As for the sulfuric slag leachate containing 2.158 g/L Fe and 0.730 g/L Cu respectively, a process consisting of oxidation, neutralization and hydrolysis for iron removal followed by sulfide precipitation was adopted for recovering copper herein. The iron removal effects by using sodium carbonate and lime milk as the hydrolytic precipitators, as well as the effects of recovering copper from sodium sulfide and sodium thiosulfate as the copper precipitation agents were investigated based on comparison. The hydrolysis for iron removal is optimally performed at 85 ℃ for 3 h, with sodium carbonate as the hydrolysis precipitant for iron removal, with H₂O₂ and iron ion at a molar ratio of 1.5 and pH of 4.0, and then the copper precipitation is optimally performed at 85 ℃ for 2 h, at pH of 4.0, with sodium sulfide as the copper precipitation agent (with the amount at the equivalent mole fraction of copper ions in the solution after iron removal). It is found that the final comprehensive iron removal rate of the lixivium is 92.98%, the comprehensive copper recovery rate is 90.34%, and the precipitated copper sulfide slag is graded 61.65% Cu, which can be directly sold as a smelting product.