氯离子浓度对氨水浸出氯化银的影响

Influence of Concentration of Chlorine Ion on Leaching of Silver Chloride by Ammonia

作者利用配合物化学理论,对氯化银在氨水中的溶解度进行一系列计算,结果表明氨水浸出氯化银时,氨浓度、pH值、氯离子浓度对氯化银溶解度都有影响。氯化银的溶解度随氨浓度的增大而增大;在7.7<pH<11时,氯化银的溶解度随pH值的增大而增大,且最佳浸银的pH=11;在氨水体系中氯离子浓度相对较小时,氯化银的溶解度随氯离子浓度的增大而减小;其中,氯离子浓度对氯化银溶解度的影响尤为重要。基于氯离子的影响,再联系实际生产,得出工业上氨水浸出AgCl的溶液不能循环使用的直接原因是溶液中Cl-的不断积累。

In this paper, the mechanism of leaching of silver chloride by ammonia and the influences of concentration of ammonia, pH value of the solution and concentration of chlorine ion on the solubility of silver were studied. The solubility of AgCl increases with the concentration of ammonia and the pH value in the range of 7.7 and 11, the optimal pH value is 11. The solubility of AgCl decreases with increasing of concentration of chlorine ion when the concentration of chlorine ion is low. The reason why ammonia can not be recycled is the accumulation of chlorine ions in the leaching solution.