火焰原子吸收光谱法测定金精矿中锑

Determination of Antimony in Gold Concentrate by Flame Atom Absorption Spectrometry

金矿常伴生锑元素,准确测定金精矿中锑含量对选矿工艺和矿产交易价格具有重要意义。金精矿经硫酸和硝酸溶解,加入的酒石酸与锑形成稳定的络合物,酒石酸-盐酸溶液替代纯水稀释样品,可有效防止锑的水解,在10%的盐酸介质中,火焰原子吸收光谱仪在217.6 nm波长下测定金精矿中锑。通过考察样品处理方法、加酸量、溶液酸度、酒石酸用量对锑测定的影响,结果表明,采用硫酸-硝酸-酒石酸消解样品,硝酸加入量10 mL、硫酸加入量5 mL、10%的盐酸介质中、酒石酸(100 g/L)加入量5 mL时,锑的方法检出限为0.004%,方法精密度(RSD,n=11)为0.78%~3.5%,加标回收率为96.2%~101%,经国家标准样品验证,测定结果的相对误差为-1.1%~0.80%,方法适合金精矿中0.050%~5.00%锑的测定,为金精矿化学分析方法提供了有效的技术支撑。

Gold deposits are often associated with antimony.Accurate determination of antimony in gold concentrate is of great significance to mineral processing technology and mineral transaction price.In this study,the gold concentrates were dissolved by sulfuric acid and nitric acid,and the added tartaric acid formed stable complex with antimony.The tartaric acid-hydrochloric acid solution replaced pure water to dilute the sample,which could effectively prevent the hydrolysis of antimony.The antimony in gold concentrate was determined by the flame atomic absorption spectrometer at 217.6 nm in 10%hydrochloric acid medium.The effects of sample treatment method,acid addition amount,solution acidity and tartaric acid amount on the results of antimony determination were discussed.The results showed that the method of sulfuric acid-nitric acid-tartaric acid was the best.The optimal experimental conditions were as followed:the volume of nitric acid and sulfuric acid were 10 mL and 5 mL,respectively,and the amount of tartaric acid(100 g/L)was 5 mL in 10%hydrochloric acid medium.The detection limit of the method was 0.004%,the precision(RSD,n=11)was 0.78%-3.5%,the recovery was 96.2%-101%,and the relative error of the result was-1.1%-0.80%by the CRM verification.This method is suitable for the determination of 0.050%-5.00%antimony in gold concentrate,and provide effective technical support for chemical analysis of gold concentrate.