【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。更多还原

【Abstract】 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,Cu2+ concentration from soluble copper in ores was sufficient,and excessive Cu2+ led to suffered gold extraction.The results showed that Cu(NH3)42+ served as oxidant,and Cu(CN)32-was extractant,and the four stage of copper and gold concentration in cyanide ammonia solution supported above mechanism.更多还原