铅阳极泥湿法处理工艺实践

铅阳极泥是提取金、银等贵金属的重要原料.控制电位在400~450 mV,使铜、锑和铋等贱金属优先于贵金属氧化浸出,贵金属得到富集.采用亚硫酸钠二次分银、甲醛还原银的工艺,得到品位98.86%的粗银,经银电解精炼,可得到99.99%的纯银.采用常温氯化分金、SO2还原得到粗金、粗金二次溶解以及草酸煮沸还原等工艺,得到纯金粉,金粉质量达到国标Au-1的标准.从铅阳极泥至金粉、粗银粉,金、银的直收率分别为95.65%和98.08%.整个工艺设计简短合理,技术指标较为理想.

Technological Practice of Processing Lead Anode Slime by Hydrometallurgy

Lead anode slime is an important raw material for extraction of gold, silver and other metals. Metals of copper, antimony and bismuth were oxidatively leached before precious metals by controlling potential in 400-450 mV and precious metals were enriched in residue. The 99.99% silver could be obtained by electrorefining crude silver of 98.86%, which was produced from lead anode slime using two steps of separating silver with sodium sulfite and reducing silver with formaldehyde. Crude gold was received by chloridizing separation of gold at room temperature and reduction with SO2. Pure gold powder up to the standard of GB Au-I was obtained by dissolving crude gold and reducing with oxalic acid at boiling temperature. With this process satisfactory results were obtained： the direct recovery rates of gold and silver from lead anode slime reached 95.65% and 98.08% respectively.