硫代硫酸钠掩蔽铜-丁二酮肟重量法测定含铜工业硫酸镍中镍

Determination of nickel in copper-containing industrial nickel sulfate by dimethylglyoxime gravimetry after masking copper with sodium thiosulfate

铜冶炼副产品工业硫酸镍中铜质量分数为1%~5%,如采用化工行业标准方法 HG/T2824—2009《工业硫酸镍》中规定的丁二酮肟重量法测定镍,则铜对镍的测定存在干扰。试验对测定含铜工业硫酸镍中镍的分析方法进行了改进,增加了使用硫代硫酸钠掩蔽铜的步骤,再采用丁二酮肟重量法测定镍,从而建立了硫代硫酸钠掩蔽铜-丁二酮肟重量法测定含铜工业硫酸镍中镍的方法。方法确定了硫代硫酸钠掩蔽铜时溶液pH值为5~6,丁二酮肟沉淀时pH值为8.5。按照实验方法测定两个工业硫酸镍样品中镍,测定结果的相对标准偏差(RSD,n=10)为0.63%和0.28%,测定值和标准方法 YS/T 252.1—2007基本一致。

The mass fraction of copper in industrial nickel sulfate of the by-product in copper smelting was1%-5%.If the content of nickel was determined by dimethylglyoxime gravimetry,which was specified in chemical industrial standard method of HG/T 2824-2009 Industrial nickel sulfate,the determination would be interfered by copper.The analysis method of nickel in copper-containing industrial nickel sulfate was modified.After copper was firstly masked with sodium thiosulfate,the content of nickel was determined by dimethylglyoxime gravimetry.Consequently,a determination method of nickel in copper-containing industrial nickel sulfate was established by dimethylglyoxime gravimetry after masking copper by sodium thiosulfate.The optimum experimental conditions were obtained：the pH for masking of copper by sodium thiosulfate was 5-6,and the pH for dimethylglyoxime precipitation was 8.5.The content of nickel in two industrial nickel sulfate samples was determined according to the experimental method,and the relative standard deviation（RSD,n=10）was 0.63% and 0.28%,respectively.The results were basically consistent with those obtained by standard method of YS/T 252.1-2007.