氰化金泥处理过程产生的银渣中金、银的回收

Recovery of Au and Ag from Silver Slag Produced in the Treatment of Cyanide Gold Mud

为了回收金精炼氯化分金后生产银锭过程中副产品银渣中的金和银,对直接氰化及先酸溶再氰化处理效果进行了对比研究。结果表明,银渣经酸处理后,在优化条件下,其金浸出率可达95%以上,银浸出率可达90%左右,明显高于直接氰化;采用直接氰化处理方法,当银渣细磨至-0.038 mm占95%以上粒度时,氰化过程中加入碳酸氢铵,且氰化分段进行洗涤,延长浸出时间,可显著提高金、银浸出率。通过多次分段洗涤-氰化浸出工业试验,银渣中金回收率高达92.93%,银回收率84.17%。采用的方法操作过程简单,试剂消耗少,经济效益显著。

In order to recover Au and Ag from silver slag, which was the by-product of the silver ingot fabrication process after the refinement of Au from chlorination solution of gold, the effects of two different processing methods were compared. One was directly cyaniding the silver slag, the other was firstly dissolving the slag in acid and then eyaniding. The results showed that, after dissolving into acid and cyaniding by the optimal condition, the leaching rate of Au was higher than 95%, and that of silver was -90%, which were both higher than direct cyanidation. While in the direct cyanidation process, by grinding the silver slag to -0.038 mm （more than 〉95%）, adding ammonium bicarbonate, multiple washing during cyaniding process, and prolonging the leaching time, the leaching rate of both Ag and Au both could be obviously increased. With multiple industrial tests with washing-cyaniding leaching process, the recovery rate of Au from silver slag reached 92.93%, and that of Ag was 84.17%. The results provided a new method for the industrial recovery of silver slag with simple operation and low reagent consumption.