常压富氧浸出含锗氧化锌烟尘回收锌和锗

Recovery of zinc and germanium from zinc oxide dust containing germanium by atmospheric oxygen enrichment leaching

针对湿法炼锌过程中稀散金属锗的浸出,以含锗氧化锌烟尘为原料,采用常压富氧浸出技术从含锗氧化锌烟尘中回收锌和锗。氧化锌烟尘的X射线衍射(XRD)和扫描电子显微镜-能谱分析(SEM-EDS)等分析结果表明,富锗氧化锌烟尘除含有氧化锌外,还含有少量硫化锌与硫化铅,部分硫化锌与氧化锌混合形成致密颗粒。考察了铜离子浓度、时间、液固比、温度、氧压等因素对氧化锌烟尘浸出锌、锗的影响。结果表明,在常压富氧条件下,温度90℃、液固比7 mL/g时,采用两段浸出4 h,锌、锗的浸出率可超过90%;浸出渣主要物相为硫酸铅和硫化锌。采用氧化锌烟尘做中和剂对酸浸溶液进行中和还原处理,控制溶液pH值为3~3.5,反应时间1 h,可将溶液中Fe3+的浓度控制在0.02 g/L内,且该过程溶液中的锗不发生水解损失,有利于后续溶液中锗的高效分离回收。

This paper studies the atmospheric oxygen leaching of germanium and zinc from germanium-bearing zinc oxide dust in the process of zinc hydrometallurgy.The raw material is germanium-bearing zinc oxide dust,which contains zinc oxide and few zinc sulfide and lead sulfide as analyzed by X ray diffraction(XRD)and scanning electron microscopy-energy disperse spectroscopy(SEM-EDS).Some zinc sulfide is mixed with zinc oxide to form dense particles.The effects of the copper ion concentration,time,liquid-solid ratio,temperature,oxygen pressure on the leaching of zinc and germanium were studied.The results show that under the condition of atmospheric oxygen leaching,90℃of the temperature,7 mL/g of the liquid-solid ratio,and 4 h by two stages leaching,zinc and germanium leaching rate could over 90%.The main phase of residue are lead sulfate and zinc oxide.Neutralizing and reduction process was employed to deal with the leaching solution of germanium.When solution pH values was 3.0~3.5 and reaction time was 1 h,the concentration of Fe3+could reduce below 0.02 g/L,and the germanium in solution did not hydrolysis,which is beneficial to the efficient separation and recovery of germanium in the subsequent solution.