氧化锌烟尘中铟锗的分离回收工艺

Separation and Recovery Process of Indium and Germanium from Zinc Oxide Dust

采用火法烟化挥发法处理湿法炼锌、火法炼铅渣后产生的氧化锌烟尘主要含锌、铁,还含有铟、锗等一种或多种稀有金属,具有较高的回收价值。常规处理氧化锌烟尘采用两段酸浸工艺处理,通常只能针对其中一种稀有金属进行单一回收,不能满足目前企业的原料变化和冶炼要求。以含铟、锗的氧化锌烟尘为原料,利用铟、锗浸出特性的不同,通过调控反应过程的酸度,分步浸出铟、锗,并通过铟、锗萃取特性的不同,进一步分离回收铟、锗,从而实现氧化锌烟尘中铟、锗的分离提取。结果表明,经三段中浸—低酸浸—高酸浸强化浸出,中浸液中铟含量在2 mg/L左右,锗含量在60 mg/L左右,可用于后续的沉淀回收锗;低酸浸出液的铟含量在280 mg/L左右,锗含量在70 mg/L左右,经过后续的中和沉淀,铟富集到10075 g t左右,中和渣进行浸出—萃取—电积得到精铟产品和含锗萃余液,萃余液返回中浸,达到了铟锗分离提取的目的,实现了对资源的综合利用。

Zinc oxide dust,produced by pyrometallurgical fuming volatilization method after zinc hydrometallurgy and lead pyrometallurgical slag treatment,mainly contains zinc,iron,as well as indium,germanium and other rare metals,which has a high recovery value.Conventional zinc oxide dust is treated by two-stage acid leaching process.Usually,only one rare metal can be recovered singly,which cannot meet the requirements of raw material change and smelting in enterprises.Taking zinc oxide dust containing indium and germanium as raw material,indium and germanium were leached step by step by adjusting acidity of the reaction process based on the different leaching characteristics of indium and germanium.The separation and extraction of indium and germanium from zinc oxide dust can be realized through the different extraction characteristics of indium and germanium.The results show that after three-stage neutral leaching,weak acid leaching,and high acid enhanced leaching,content of indium and germanium in leaching solution is about 2 mg/L and 60 mg/L,which can be used for subsequent precipitation and recovery of germanium.The content of indium and germanium in low acid leaching solution is about 280 mg/L and 70 mg/L.After subsequent neutralization precipitation,indium is enriched to about 10075 g t.Refined indium product and germanium-containing raffinate can be obtained by leaching,extraction,and electrodeposition of neutralizing residue,and the raffinate is returned to neutral leaching,which achieves the purpose of separation and extraction of indium and germanium,and realizes the comprehensive utilization of resources.