燃烧-碘量法测定金矿石中的硫含量

Determination of sulfur content in gold ore sample by combustion-iodine analysis method

为快速、准确测定金矿石样品硫含量,采用铜片作为助熔剂,空气为氧化性气体,于1250℃加热燃烧,将金矿石样品中的硫转化为二氧化硫,用酸性碘化钾-淀粉溶液吸收二氧化硫,用碘酸钾标准溶液滴定。进行了空气流量、助熔剂的种类及用量和称样量的选择性试验,建立了燃烧-碘量法测定金矿石中硫含量的方法。确定了实验最佳条件:空气流量1.8 L/min,称样质量为0.20 g,铜片用量为0.40 g,炉温1250℃。在选定的实验条件下,对金矿石样品中硫含量进行了测定,测定结果的相对标准偏差为0.34%~3.09%(n=11),方法的加标回收率为95%~103%,测定范围为0.10%~25.30%。本方法与国家标准方法GB/T 20899.8—2007进行了对照实验,对照结果准确,硫含量的检测范围更宽。

In order to quickly and accurately detect the sulfur content of gold ore samples,copper sheet is used as flux and the air is used as oxidizing gas,which is heated and burned at 1250℃.Sulfur in gold ore sample is converted into sulfur dioxide,which is absorbed by acidic potassium iodide-starch solution and titrated with potassium iodate standard solution.The selective test of air flow rate,type and dosage of flux and sample mass weight are carried out,and a combustion-iodometric method for the detection of sulfur content in gold ore is established.The optimal experimental conditionis determined as followed,air flow rate 1.8 L/min,sample mass weight 0.20 g,copper sheet dosage 0.40 g,furnace temperature 1250℃.Under the selected test condition,the sulfur content in gold ore sampleis analyzed and determined,the relative standard deviation of the analysisdatais 0.34%-3.09%(n=11),the recovery rate of analysis method is 95%-103%,and the detection range is 0.10%-25.30%.This analysis method is compared with the national standard method GB/T 20899.8—2007.The controlling result is accurate and the detection range of sulfur is wider.