铜精矿中铜的电解重量法测定及其与碘量法测定的比较

Determination of Copper Content in Copper Concentrates by Electrogravimetric Method and Its Comparison with Iodometric Method

采用电解重量法,以硝酸、硫酸消解试样,加入氢溴酸除去杂质元素,氨水分离过滤,含铜滤液进行电解称重,并辅以电感耦合等离子体原子发射光谱法测定残渣、残液中的回收铜,得到铜精矿中的铜含量。通过标准样品准确度实验,可知电解重量法测定铜精矿铜含量准确可靠,并对抽取的10个铜精矿样品进行测定,并将其测定结果与经典碘量法测定结果对比,绝对偏差均在±0.15%以内,测定结果吻合。通过精密度比较发现,电解重量法所得标准样品GBW07166和检测样Cu-10相对标准偏差分别为0.20%、0.19%,均较碘量法0.34%、0.28%小,具有更高的精密度。因此,推广电解重量法测定铜精矿中铜含量很有必要。

In this paper,the copper content in copper concentrates is determined by electrogravimetric method.The sample is digested with nitric acid and sulfuric acid.Impurity elements are removed by adding hydrobromic acid.The solution is added with excess ammonia and filtered.The copper-containing filtrate is then electrolyzed and deposited copper weighted.The trace of copper in the residue and residual liquid is determined by inductively coupled plasma atomic emission spectrometry.From the experiment of accuracy,it can be concluded that electrogravimetric method is accurate and reliable.The results of 10 copper concentrate samples are in consistent with those by iodometric method,with deviations all less than0.15%.In the precision experiment,the RSD results by electrogravimetric method of sample GBW07166 and Cu-10 are 0.20%,0.19%,respectively,less than 0.34%,0.28%by iodometric method,indicating a higher precision of electrogravimetric method.Therefore,it is necessary to promote the electrogravimetric method to determine the copper content in copper concentrates area.