氰化尾渣还原焙烧酸浸提铁及氰化浸金新工艺

摘要

The cyanide tailings were treated by reduction roasting and acid leaching. The cyanide tailings were reduced under conditions of reduction temperature 850℃, the mass ratio of pulverized coal to cyanide tailings 13%and reduction time 100 min. Fe2O3 in the cyanide tailings is turned into Fe3O4 or FeO. The reduced cyanide tailings were leached by sulfuric acid under conditions of a concentration of sulfuric acid 50%, the sulfuric acid dosage coefficient 1.2, leaching temperature 105℃and leaching time 3 h. The leaching rate of Fe is 93.66%. The leaching rate of Au is 92.4%under conditions of sodium cyanide dosage 4 kg/t, leaching time 28 h, the ratio of liquid to solid 2:1 after acidic residue is roasted at 600 ℃for 2 h to remove carbon. The mass of cyanide tailings decreases by 38.8%after reduction roasting, sulfuric acid leaching, oxidizing roasting and cyanide leaching.%以氰化尾渣为原料，采用还原焙烧酸浸工艺对其进行处理。当还原温度为850℃、加入煤粉质量为氰化尾渣质量的13%、还原时间为100 min时，对氰化尾渣进行还原，氰化尾渣中Fe2O3转化为Fe3O4或FeO。还原后采用硫酸浸出，当硫酸浓度为50%、硫酸用量系数为1.2、反应温度为105℃、反应时间为3 h时，铁的浸出率达到93.66%。还原焙烧渣在600℃氧化焙烧2 h经过脱碳后氰化浸金，当氰化钠用量为4 kg/t、反应时间为28 h、液固比为2：1时，金的浸出率达到92.4%。经过还原焙烧、硫酸浸出、氧化焙烧及氰化浸金，氰化尾渣渣量减少了38.8%。