水合肼湿法还原金试验研究

Experiment of Gold Reduction by Hydrazine Hydrate in Hydrometallurgical Method

选取水合肼作为还原剂还原王水溶金,考查了反应温度、时间、水合肼浓度配比、王水酸度、水合肼用量等因素对金泥杂质Cu+含量及含金废水金含量影响,获得了优化工艺条件。在优化工艺条件下开展了工业试验,并与常用的Na2SO3还原进行对比,结果表明,用水合肼还原王水溶金其杂质Cu、Ag含量分别为0.002 9%和0.012 4%,略高于Na2SO3还原,不会对金泥的品质造成影响。但其优势却颇为明显:无需加热,不会分解成SO2、不带入杂质、还原废水中金含量降低57%,且操作简单,劳动强度小。

Hydrazine hydrate was selected to reduce gold in aqua regia. The effect of temperature, time, concentration of hydrazine hydrate, acidity of aqua regia and hydrazine hydrate amount on Cu content in gold slime and gold content in gold- containing wastewater was investigated and the optimal condition was obtained. The industrial test was carried out under that condition and the results showed that the content of Cu and Ag in impurities is 0.002 9% and 0.012 4%, which is a little higher than that by using Na2SO3 as reduction agent and will not affect the quality of gold slime. The advantages of using hydrazine hydrate are obvious including no need for heating, no decomposition of S02, no addition of impurity, the content of gold in reduced wastewater can be decreased 57% and the operation is simple with small labor intensity.