单宁锗渣酸洗制备高品位锗精矿试验研究

Preparation of High-grade Germanium Concentrate by Acid Pickling of Tannic Germanium Residue

针对单宁锗渣水洗过程存在的杂质去除率低、锗精矿品位低等问题,研究了采用稀硫酸溶液洗涤高效脱除单宁锗渣中As、Zn、Fe杂质,考察了硫酸质量浓度、洗涤温度、洗涤时间、液固体积质量比对As、Zn、Fe杂质脱除率及Ge损失率的影响。结果表明:采用三段逆流硫酸洗涤,在硫酸质量浓度60 g/L、液固体积质量比5 mL/1 g、洗涤温度60℃、一段洗涤时间120 min、二段和三段洗涤时间均为60 min条件下,As、Zn、Fe累计脱除率分别可达88%、97%、95%以上,Ge累计损失率在1.50%以下;采用三段逆流酸洗—氧化焙烧工艺制备的锗精矿中Ge、As品位分别34.45%、0.54%,符合锗精矿三级标准。

In view of the problems of low impurity removal rate and low grade of germanium concentrate in the washing process of tannin germanium residue,the As,Zn and Fe impurities in tannin germanium residue were effectively removed by washing with dilute sulfuric acid solution.The effects of sulfuric acid mass concentration,washing temperature and washing time,liquid volume to solid mass ratio on the removal rate of As,Zn and Fe impurities and Ge loss rate were investigated.The results show that under the conditions of sulfuric acid mass concentration of 60 g/L,liquid volume to solid mass ratio of 5 mL/1 g,washing temperature of 60℃,first washing time of 120 min,second washing and third washing time of 60 min,the cumulative removal rates of As,Zn and Fe can reach over 88%,97%and 95%,respectively.Ge cumulative loss rate is less than 1.50%.The Ge and As grades of germanium concentrate prepared by three-stage countercurrent pickling and oxidation roasting process are 34.45%and 0.54%,respectively,which meet the tertiary standard of germanium concentrate.