高镍铜阳极泥中硒、碲、铜的顺序脱除

Sequential Removal of Se,Te and Cu from Copper Anode Slime with High Nickel Content

针对高含镍铜阳极泥,采用直接添加氢氧化钠焙烧-碱浸-酸浸流程进行Se、Te、Cu的脱除试验研究,并对过程的反应机理进行了分析。研究发现,加碱氧化焙烧过程中硒化物和碲化物中的Cu变成Cu O和Cu3Te O6;Se、Te分别转变成在碱性溶液中易溶的Na2Se O3和不溶的Ag2Te O3、Cu3Te O6,为Se、Te、Cu的选择性脱除奠定了基础。试验结果表明,最佳焙烧-碱浸的条件为:Na OH剂量为阳极泥的10%,焙烧时间1.5h,焙烧温度500℃。碱浸时间1.0h、Na OH浓度20g/L、碱浸温度80℃、液固比5∶1。在此条件下Se的浸出率为95.50%,碱浸渣中Se的含量从3.93%下降到0.23%。碱浸渣酸浸除铜碲的最佳条件为:H2SO4浓度为90g/L、酸浸温度70℃、酸浸时间1.0h、液固比20∶1;在此条件下,Cu、Te的脱除率分别为96.18%、98.48%。

A process including roasting with NaOH- alkaline leaching- acid leaching has been tested for removing Se,Te and Cu from copper anode slime with high nickel content. The reaction mechanism of this process was also discussed. During roasting with caustic soda,copper in Cu2Se and Cu2Te turned into Cu O and Cu3TeO6,while Se and Te changed into Na2SeO3,Ag2TeO3 and Cu3TeO6. Na2SeO3 is easily leached in alkaline solution while Ag2TeO3 and Cu3TeO6 can not be leached in such a process,this difference lays the foundation for selective removal Se and Te. The results showed that the optimal roasting- alkaline leaching condition are as following： NaOH dosage / anode slime is 10%,roasting period is 1. 5h and roasting temperature is at 500℃; alkaline leaching period is 1. 0h,NaOH concentration is 20 g / L,alkaline leaching temperature is at 80℃ and the pulp concentration is 20% 。Under this condition 95. 50% of Selenium was leached out and not more than 1% of Tellurium leached out. The content of selenium in alkaline leaching residue decreased from 3. 93% to 0. 23%. The optimal acid leaching condition is that H2SO4 concentration is 90 g / L,acid leaching temperature is at 70℃,leaching period is 1. 0h with pulp concentration at 5%. The removal efficiency of copper and tellurium under this condition are 96. 18% and 98. 48%,respectively.