碘化浸出液电沉积金工艺

Electrodeposition of gold in iodine leaching solution

针对碘化浸出液中金回收效率低、电能消耗高等问题,采用电沉积法从碘化浸出液中电沉积金。考察阴极液金浓度、阳极液碘质量分数、阳极液n(I2):n(I^-)、槽电压对金沉积率的影响。采用响应面法以阳极液碘质量分数、阳极液n(I2):n(I^-)、槽电压为变量因素,金沉积率为响应值,研究各变量因素之间的交互作用以及对金沉积率的影响规律。结果表明:阳极液碘质量分数、阳极液n(I2):n(I^-)和槽电压与金沉积率的主效应关系为:槽电压>阳极液n(I2):n(I^-)>阳极液碘质量分数,并得出了以金沉积率为响应值的二阶回归方程。优化后工艺条件为:阴极液金浓度10 mg/L、阳极液碘质量分数0.58%、阳极液n(I2):n(I^-)1:6.5、槽电压12 V、电解时间2 h,三次验证实验的金沉积率均值为97.83%,与模型预测值98.15%十分接近,证明响应面法优化得到的二次多项式模型具有可行性。同时,该工艺条件适用于实际应用,金沉积率仍可达97%以上。

In order to solve the problems of low recovery efficiency and high consumption of electric energy,gold was electrodeposited from the iodine leaching solution by electrodeposition.The effects of catholyte gold concentration,anolyte iodine mass fraction,anolyte n(I2):n(I^-),and cell voltage on the gold deposition rate were investigated.Using the response surface method,the iodine mass fraction of the anode liquid,the n(I2):n(I^-)in anode liquid,and the tank voltage were taken as variable factors,and the gold deposition rate was taken as the response value.The results show that the main effects of iodine mass fraction,anolyte n(I2):n(I^-),and cell voltage on the gold deposition rate from greater to littler are cell voltage,anolyte n(I2):n(I^-),anodic liquid iodine mass fraction,and a second-order regression equation with a response rate of gold deposition was obtained.The optimized process conditions are as follows catholyte gold concentration of 10 mg/L,anolyte iodine mass fraction of 0.58%,anolyte n(I2):n(I^-)of 1:6.5,cell voltage of 12 V,electrolysis time of 2 h.The three times average gold deposition rate in the verification experiment is 97.83%,which is very close to the model prediction value of 98.15%,which proves that the quadratic polynomial model optimized by the response surface method is feasible.At the same time,the process conditions are suitable for practical application,and the gold deposition rate can still reach more than 75%.