碘量法测定铜阳极泥中铜的方法改进

Method improvement for determination of copper incopper anode slime by iodometry

使用行业标准方法YS/T 745.1-2010碘量法测定铜阳极泥中铜时,采用氢溴酸除去试样中硒、砷、锑、锡等干扰元素,溶样过程操作繁琐,耗时长,易发生溅跳而造成无效结果,且检测效率低,因此不适用于冶炼企业大批量样品同时快速分析检测。试验使用盐酸分解试样,用硝硫混酸初步除硒等杂质、再用溴进一步除杂,替代氢溴酸除去试样中的杂质元素,从而对YS/T 745.1-2010碘量法测定铜阳极泥中铜的方法进行了改进。通过试验确定硝硫混酸用量为15 mL,而后加入3 mL盐酸溶解至溶液体积剩余约0.5 mL时能完全溶解盐类。按照实验方法测定铜阳极泥试样中铜,测定结果的相对标准偏差(RSD,n=7)小于0.50%;各试样测定结果与行业标准方法YS/T 745.1-2010结果一致,且两种方法间不存在显著性差异,可用于冶炼企业大批量快速分析检测铜阳极泥中铜量。

During the determination of copper in copper anode slime by iodometry according to the industrial standard method YS/T 745.1-2010,hydrobromic acid is used to remove interfering elements such as selenium,arsenic,antimony and tin.The sample dissolution process is tedious and time-consuming.The splashing occurs easily,leading to invalid results and low detection efficiency.So,it is not suitable for simultaneous and rapid analysis and detection of a large number of samples in smelting enterprises.In the experiment,hydrochloric acid was used to decompose the sample.After removing the impurities such as selenium by mixed nitric acid and sulfur acid,the impurity elements in sample was further removed using bromine instead of hydrobromic acid.Consequently,the determination method of copper in copper anode slime by iodometry according to YS/T 745.1-2010 was modified.The dosage of mixed nitric acid and sulfur acid was 15 mL.Then the salts could be fully dissolved after adding 3 mL of hydrochloric acid and dissolving the sample until the remaining volume of the solution was about 0.5 mL.The content of copper in copper anode slime sample was determined according to the experimental method.The relative standard deviation(RSD,n=7)of the determination results was less than 0.50%.The found results of each sample were consistent with those obtained by industrial standard method YS/T 745.1-2010.There was no significant difference between two methods,and the proposed method could be applicable for the rapid analysis of copper in a large number of copper anode slime samples in smelting enterprises.