氯金酸钠代替氯金酸测定矿石中金含量的研究

矿石中金含量的测定通常采用王水溶解，使其形成氯金酸后再用原子吸收法或容量法进行测定，但是氯金酸溶液稳定性容易受温度、酸度、浓度、外界条件和容器吸附等因素的影响。为了提高氯金酸溶液的稳定性可用碱金属使其生成相对稳定的氯金盐，但未真正实践应用。本文提出了一种以氯金酸钠代替氯金酸做标准溶液测定矿石中金含量的方法，应用本方法配制的标准溶液放置3～4个月未出现还原偏低现象。该方法采用活性炭吸附柱富集金，用王水溶解，再加入饱和氯化钠溶液制得氯金酸钠溶液。采用原子吸收法，在日立Z-2000原子吸收分光光度计上测定金的含量。实验结果表明：该测定方法可靠，误差较小，稳定性好；测定的绝对灵敏度可达0.025 μg/g，测定范围为0.04～1 000 μg/g，适合用于大批量地质矿石样品中金的测定。

The Gold Determination in Ores Using NaAuCl Instead of HAuCI by AAS

The gold content in the ore is usually determinated by atomic absorption or volumetric method using the aqua regia dissolution method to generate gold chloride acid firstly,whose stability easily affected by temperature, acidity,concentration external conditions and container adsorption.In this paper,the method using gold chloride sodium instead of gold chloride acid for the determination of gold in ore content was developed.The standard solu- tion prepared by the method was placed for three or four months still not turn to lower reduction.In this method, gold was enriched by activated carbon adsorption column,dissolved in aqua regia,and then gold chloride of sodi- um was prepared by adding the saturated sodium chloride solution.The determination of gold content was pro- cessed using the atomic absorption method in the Hitachi Z-2000 atomic absorption spectrophotometer.The experiments showed that the method is reliable, and owns small error and good stability.Depended on the absolute determination sensitivity of 0.025 μg/g and measuring range of 0.04-1 000 μg/g,this method was suitable for the gold determination in large quantities of geological ore samples.