含锑难处理金矿选择性脱除锑

摘要

In order to avoid the negative influence of antimony on the cyanide process, the method of sodium sulfide leaching was proposed to selective remove antimony from refractory gold ores. The key factors influencing the leaching ratio of antimony were investigated, and these leaching ratios of gold and arsenic were also studied under the optimum condition. The results show that the excess coefficient of Na2S, NaOH mass concentration, temperature, liquid-to-solid ratio and washing water ratio benefit the leaching ratio of antimony. But the leaching ratio of antimony decreases with the increase of reaction time and enhancing stirring speed. Antimony mass fraction in the leach residue can be decreased to 0.04% by increasing washing water ratio to 4.0. Under the optimum condition, the leaching ratio of antimony reaches 96.64%, but those of gold and arsenic are only 1.44% and 0.41%, respectively. XRD analysis reveals that black mixture precipitated from the leach solution is composed of Na2FeS2, S and FeS2, indicating that less FeS2 first dissolves during leaching and then precipitates from the solution.%为了消除锑对难处理金矿提取金过程的不利影响,提出用硫化钠浸出方法预先从含锑难处理金矿中选择性脱除锑,考察各因素对锑浸出率的影响,查明最优浸出条件下金和砷的浸出率.研究结果表明:硫化钠过量系数、氢氧化钠质量浓度、温度、液固比和洗水比等因素的增加均有利于提高锑的浸出率,但是延长反应时间和增大搅拌速度会使锑浸出率略降低,增大洗水比至4.0可以将浸出渣中锑质量分数降低至0.04%.含锑难处理金矿硫化钠浸出在最优条件下,锑的浸出率可以达到96.64%,金和砷的浸出率分别为1.44%和0.41%.浸出液静置后析出的黑色沉淀为Na2FeS2,S和FeS2的混合物,说明会有少量FeS2矿物首先溶解然后从溶液中沉淀出来.