铅阳极泥H2SO4 NaCl选择性浸出研究

采用选择性脱铜—H2SO4+NaCl选择性浸锑、铋—硝酸脱铅—火法熔炼回收贵金属工艺综合回收铅阳极泥中的有价金属。重点介绍了该工艺中H2SO4+NaCl选择性浸锑、铋试验研究。确定了最佳浸出条件:初始硫酸浓度2.5～3 mol/L,NaCl浓度为75～100 g/L,浸出温度80℃,液固比L/S=8/1(mL/g),浸出时间2 h;在该条件下锑、铋、铜的平均浸出率均大于99%,铅的平均浸出率仅1.68%,金银不被浸出,锑、铋、铜得以有效选择性浸出,铅、金、银在渣中得到了有效富集,为后续工艺中硝酸脱铅和贵金属火法综合回收工艺创造了有利条件,解决了传统铅阳极泥湿法综合回收出现的金属分离不彻底,贵金属直收率不高等问题。

STUDYON SELECTIVE LEACHING FROM LEAD ANODE SLIMEBY H2SO4 NaCl

The process of Cu selective removal-selective leaching Sb,Bi by H2SO4+ NaCl-Pb removal by nitric acid-precious metal recover by smelting method is used to comprehensively recover valuable metals from lead anode slime.In this paper,the experimental study on selective leaching Sb,Bi by H2SO4+ NaCl is focused.The best leaching conditions are determined: initial acidity of H2SO4 2.5～3(mol/L),NaCl concentration 75～100(g/L),leaching temperature 80 ℃,liquid-solid ratio L/S=8/1(mL/g),leaching time is 2 hours,under this condition,the average leaching rate of Sb,Bi and Cu are all over 99%,the average leaching rate of Pb is only 1.68%,Au and Ag are not be leaching;So Sb,Bi and Cu are effectively selectively leached,Pb,Au and Ag are effectively enriched in leaching slag,which creates favorable conditions for subsequent comprehensively recovery process of Pb removed by nitric acid and precious metals recovered by pyrometallurgy method,which solves the problems occurring during the traditional process such as metal incompletely separated and low precious metals direct recovery.