提高分金工序中碲浸出率的试验研究

铜阳极泥经过硫酸化焙烧—酸浸分铜后,分金工序中碲浸出率较低。为了提高碲浸出率,在现有工艺主流程不变的条件下,主要考察分金工序中的液固比、硫酸浓度、氯化钠加入量、分金时间等对分金后液中碲浸出率的影响。研究结果表明,以酸度为1 mol/L,NaCl加入量为20%、液固比5∶1、NaClO_3加入量为4%,80℃下反应2 h,控制终点电位在1 100 mV左右,为控电位氯化氧化分金最佳试验条件,此时金、铂、钯基本被浸出至溶液中,碲的浸出率可达到94%以上,铋的浸出损失为12%左右。

Study on Improving Leaching Rate of Tellurium in Process of Leaching Gold by Chlorination

After recovering copper from copper anode slime followed sulphation roasting,the leaching rate of tellurium in process of leaching gold by chlorination was low. In order to improve the leaching rate of tellurium,the influence of the liquid and solid ratio,the concentration of sulfuric acid,the amount of sodium chloride and the time in process of leaching gold by chlorination was investigated mainly under the condition that the main technological process remained unchanged. The results showed that the optimum experimental conditions were as follows: the acidity of 1 mol / L,NaCl addition amount of 20%,the liquid-solid ratio 5∶ 1,NaClO3 addition amount of 4%,the reaction time of 2 h under 80 ℃,and the end point potential of about 1 100 mV. Under these conditions,gold,platinum and palladium were basically leached into the solution,and the leaching rate of tellurium was more than 94%,and the leaching loss of bismuth was about 12%.