硫脲法处理银精矿的研究

以某厂湿法炼锌浸出渣浮选所得的银精矿为原料,用硫脲对其进行络合浸出,并用锌粉分步还原回收浸出液中的银和铜。结果表明,银浸出率保持在90%左右,锌粉分步还原可得到含银80%左右的银绵和含铜60%左右的铜渣。银绵经火法处理得粗银锭,再经电解可得精银,二次还原后液可直接返回浸出流程,可使硫脲得到循环利用。经生产中试,该工艺可应用于工业生产并取得较好的经济效益。

Study on Treatment of Silver Concentrate with Thiourea Process

The silver floatation concentrate from leaching slag of zinc hydrometallurgy was leached with thiourea process. Silver and copper was recovered from leaching solution by means of zinc powder stepping reduction. The results show that the leaching rate of silver is about 90% under the optimum conditions, the silver sponge grade is about 80% and copper grade in copper slag is 60%. Treated with pyrometallurgy first, the silver sponge is then electrolysis refined to get silver ingot. The secondary reduction solution can be directly returned to leaching process and the thiourea is recycled. This technology can be commercialized to achieve better economic benefit after pilot plant test.