摘要
对于金以非包裹形式存在的含铜金矿石,直接氰化虽然能取得较高的金浸出率(92%),但氰耗高(130 kg/t),而且氰化物耗量并不与铜的浸出量成线性关系。氨氰体系浸金可以得到较高金浸出率的同时,降低氰化物耗量。该体系中最佳氨氰比为3∶1,最大的氰化钠用量为14.7 kg/t,继续增大氰化钠用量,金的浸出率并不明显增高,而过量的氨则会导致试样中铜的快速溶解,同样不利于金的浸出。试样中的可溶性铜使浸出液中的Cu2+浓度满足氨氰体系浸金的要求,过量的Cu2+对浸金不利。研究结果表明,氨氰体系浸出金的机理可能是铜氨络离子充当氧化剂,而氰铜络离子(以Cu(CN)32-为主)充当浸金剂,浸出液中铜浓度和金浓度变化的四个阶段支持了此浸金机理。
Gold leaching rate was up to 92% with direct cyanide for copper-gold ores,but large quantities of cyanide,about 130 kg/t,were consumed,and the consumption of cyanide wasn t linear with the Cu extraction.In cyanide ammonia system,gold extraction were as high as it in free cyanide solution and the best ammonia to cyanide ratio was 3∶1,and the most consumption of cyanide was 14.7 kg/t.The gold leaching rate wasn′t improved increasing the cyanide additions,and it wasn′t beneficial in proving the gold extraction to increase ammonia concentration. In cyanide ammonia solution,Cu^2＋ concentration from soluble copper in ores was sufficient, and excessive Cu^2＋ led to suffered gold extraction. The results showed that Cu（NH3）4^2＋ served as oxidant,and Cu（CN）3^2- was extractant, and the four stage of copper and gold concentration in cyanide ammonia solution supported above mechanism.
出处
《有色金属（冶炼部分）》
CAS
北大核心
2009年第4期30-33,共4页
Nonferrous Metals（Extractive Metallurgy)
关键词
铜金矿
氨氰化系
氨氰比
机理
Copper-gold ores
Cyanide-ammonia system
Ammonia to cyanide ratio
Mechanism
