从银精矿中浸出金银的工艺优化试验研究

Process Optimization for Leaching of Gold and Silver From Silver Concentrate

研究了采用直接氰化浸出及浸出渣焙烧—硫酸浸出—氰化浸出工艺从银精矿中回收银。试验结果表明:银精矿先氰化浸出部分裸露的银,再对氰化浸出渣进行焙烧、酸浸及氰化浸出,银总浸出率达85.06%;直接氰化浸出最佳条件为pH=10,氰根质量浓度1.5g/L,氰化浸出时间36h;氰化浸出渣的最佳焙烧条件为钠盐(片碱)添加量7kg/t,在马弗炉中焙烧1h,焙烧温度630℃;焙烧渣用硫酸浸出,最佳条件为硫酸质量浓度8g/L,浸出时间1.5h;酸浸渣氰化浸出最佳条件为pH=10,氰根质量浓度2g/L,氰化浸出时间36h。

A series of experiments were carried out by the process of direct cyanide leaching-roastingacid leaching-cyanide leaching for leaching silver from a silver concentrate from Fujian.The experimental results show that the leaching rate of silver can be improved effectively by the direct cyanide leaching process.Direct cyanide leaching conditions are system pH of 10,cyanide concentration of 1.5g/L,leaching time of 36 h.The roasting conditions are caustic soda usage of 7kg/t,roasting for1 hat 630 ℃ in muffle furnace.For the roasting product,the leaching conditions are sulfuric acid concentration of 8g/L,leaching time of 1.5h.For the acid leaching residue,the leaching conditions is system pH of 10,cyanide concentration of 2g/L,leaching time of 36 h.Final,leaching rate of silver can reach 85.06%。