酒石酸络合掩蔽锑-氢醌容量法测定锑矿石样品中的常量金

应用王水溶样-活性炭富集金-氢醌容量法测定高品位锑矿石的金量时,通常受到较高含量的锑硫砷汞等元素的干扰,硫砷汞碳及有机质可以通过阶梯升温焙烧去除,但是对锑则无明显去除作用。本研究在相关实验环节通过加入酒石酸使锑的干扰问题得到解决,包括:王水溶矿时加入酒石酸络合锑,防止锑的化合物在酸度或温度降低时水解,保证吸附金的活性炭灰化后的锑量小于0.3 mg;活性炭灰化除碳后,用王水溶解金时再加入酒石酸,消除了氢醌容量法滴定过程中少量锑的干扰。本方法只需在溶矿时加入一定量酒石酸,与氢溴酸除锑、盐酸等除锑方法相比具有原理简明、测试快速等特点,用于分析实际锑矿石的精密度(RSD)小于5%,加标回收率为92.0%~107.0%。

Determination of Gold in Antimony Ores by Hydroquinone Volumetric Method with Antimony Tartrate as Complexing and Masking Agent

The traditional method of determining gold in antimony ores commonly includes sample digestion by aqua regia, preconcentration of gold by activated carbon, and measurement by hydroquinone volumetric technique. The traditional method suffers from the high contents of antimony, sulfur, arsenic, and mercury. Sulfur, arsenic, mercury, and carbon can be removed by stepwise heat, but antimony cannot be removed. In this study, tartaric acid is added to eliminate the interference of antimony. Adding tartaric acid to aqua regia during sample digestion can prevent proteolysis of antimony compounds as the acidity or temperature decreases. This step can ensure that the antimony quantity is less than 0.3 mg after the ashing of activated carbon that has adsorbed gold. After being ashed, tartaric acid is again added in aqua regia to dissolve gold, eliminating the interference of antimony on gold during hydroquinone volumetric determination of gold. The proposed method suggests adding tartaric acid at the sample digestion stage is simple and rapid relative to the method of antimony elimination by hydrobromic acid and hydrochloric acid. The relative standard deviation of natural sample analysis is less than 5% and standard-addition recovery is 92.0%-107.0%.