铜阳极泥脱铜渣中金、银、钯含量测定

Determination of gold,silver and palladium in copper anode low grade copper slag

建立了连续测定铜阳极泥脱铜渣中金、银、钯含量的分析方法,并与火试金法进行比较。首先,利用硝酸+乙二胺四乙酸(EDTA)+酒石酸消解铜阳极泥脱铜渣,得到含有银、钯和少量金的消解液,考察了硝酸、EDTA和酒石酸用量对消解效果的影响。结果表明,硝酸、EDTA和酒石酸用量分别为30m L、3m L、1.5g时,消解效果最好。然后,利用王水对残渣进行二次消解,得到含有金和少量银、钯的消解液,考察了王水用量对消解效果的影响。结果表明,王水用量为15m L时即可完成消解。最后采用火焰原子吸收光谱仪测定消解液中的金、银、钯含量。采用本方法测定铜阳极泥脱铜渣,Au、Ag、Pd各元素相对标准偏差均小于1%(n=10),加标回收率在95.57%~98.70%之间,实验结果准确可靠、重现性好,与火试金法测定结果相一致。

The method of continuous determination of gold,silver and palladium in copper anode low grade copper slag was established and compared with the fire test method. First,the copper anode low grade copper slag was digested with nitric acid＋EDTA＋tartaric acid to obtain a digestion solution containing silver,palladium and a small amount of gold. The effects of nitric acid,EDTA and tartaric acid dosage on digestion were investigated. The results showed that the digestion was the best when the dosage of nitric acid,EDTA and tartaric acid were 30 m L,3 m L and 1.5 g,respectively. Then,the residue was subjected to secondary digestion with aqua regia to obtain a digestion solution containing gold and a small amount of silver and palladium. The effects of aqua regia dosage on digestion were investigated. The results showed that the amount of aqua regia required to complete the digestion was 15 m L. Finally,the contents of gold,silver and palladium in digestion solution were determined by flame atomic absorption spectrometer. The relative standard deviations of Au,Ag and Pd in the copper anode low grade copper slag were less than 1%（n=10）,and the recoveries were between 95.57% and 98.70% by this method. The experimental results are accurate,reliable and reproducible,which is consistent with the results of fire test method.