电解槽参数对碘化浸出液中金沉积效果的影响

Effect of electrolytic cell parameters on gold deposition in iodized leaching solution

针对碘化浸出液中金回收难的问题,设计了一种从碘化浸出液中回收金的电解槽,电解槽的参数选择合理与否直接影响到实验结果。采用单因素实验法考察离子交换膜种类、阴极材料、阳极材料和两极板间距离对电流效率和金沉积率的影响,确定电解槽的离子交换膜种类、阳极材料、阴极材料和两极板间距离,分析反应过程中电流效率和金沉积率的变化规律。结果表明,采用阴离子交换膜、石墨板作阳极、钛板作阴极,电流效率和金沉积率在5%~8%和95%以上,两极板间距离对沉积金效果的影响不大。在优选条件下,电解2 h后,电流效率和金沉积率分别为5.12%和95.04%,实现了为碘化法浸取金整个工艺实现规模化生产提供数据支持。仍存在的问题是阴极的析氢反应会引起过多的电能损耗,造成电流效率降低,应寻找一种抑制析氢反应而又不影响金沉积的阴极材料。

In order to solve the problem that it is difficult to recover gold from iodized leaching solution,an electrolytic cell for recovering gold from iodized leaching solution is designed.Whether the parameters of the cell are reasonable or not directly affects the experimental results.The effects of ion exchange film type,cathode material,anode material and distance between polar plates on current efficiency and gold deposition rate were investigated by single factor experiment.The types of ion exchange membrane and anode material in electrolytic cell were determined.The distance between cathode material and polar plate was analyzed,and the variation of current efficiency and gold deposition rate during the reaction process was analyzed.The results show that when anion exchange film is used,graphite plate is used as anode and titanium plate is used as cathode,the current efficiency and gold deposition rate are 5%~8% and above 95%.The distance between the two plates has little effect on the gold deposition effect.Under the optimum conditions,after 2 h of electrolysis,the current efficiency and gold deposition rate are 5.12% and 95.04%,respectively,which provides data support for the large-scale production of the whole process of gold leaching by iodization method.The still problem is that the hydrogen evolution reaction of the cathode will cause too much power loss and reduce the current efficiency.A cathode material should be found to inhibit the hydrogen evolution reaction without affecting the gold deposition.