铅试金-电感耦合等离子体原子发射光谱法测定高镍锍中金铂钯

采用铅试金法富集高镍锍中金、铂和钯时,因高镍锍中镍、铜含量较高,严重影响着铅试金的熔炼富集和灰吹效果。实验采用盐酸溶解分离高镍锍中镍、铜等基体组分,得到的含贵金属残渣经包铅灰吹法进一步富集与分离,最终实现了铅试金-电感耦合等离子体原子发射光谱法(ICP-AES)对高镍锍中金、铂和钯的准确测定。实验探讨了盐酸用量、铅箔用量、灰皿类型、灰吹损失、银加入量、分析谱线等因素对测定结果的影响。结果表明,对于5 g高镍锍样品,80 mL盐酸几乎可以将镍、铜等基体组分溶解完全;残渣经0.45 μm滤膜收集后,加入5 mg银并包于6.0 g铅箔中,在950 ℃的镁砂灰皿中灰吹,铅及少量贱金属硫化物被氧化分离而金、铂和钯几乎不损失,形成的银合粒经混合酸分解后,银以氯化银沉淀的形式分离不干扰测定;在王水(1+9)介质中,于分析线Au 267.595 nm、Pt 265.945 nm、Pd 340.458 nm处,采用ICP-AES测定金、铂和钯。各元素校准曲线的相关系数均在0.999以上;方法检出限为0.067 μg/g(Au)、0.085 μg/g(Pt)、0.107 μg/g(Pd)。方法用于测定高镍锍中金、铂和钯,结果的相对标准偏差(RSD,n=7)为2.8%~5.9%。测定结果与行业标准方法(YS/T 252.8—2020)对照测定结果基本吻合。

Determination of gold,platinum and palladium in high nickel matte by inductively coupled plasma atomic emission spectrometry with lead fire assay

During the enrichment of gold, platinum, and palladium in high nickel matte by lead fire assay, the smelting enrichment and cupellation effect of lead fire assay are seriously affected due to the high content of nickel and copper in high nickel matte. The matrix components of nickel and copper in high nickel matte were dissolved and separated using hydrochloric acid in experiments. The residue containing precious metals was further enriched and separated by wrap lead cupelling method. The accurate determination of gold, platinum, and palladium in high nickel matte by lead fire assay-inductively coupled plasma atomic emission spectrometry (ICP-AES) was finally realized. The effect of hydrochloric acid dosage, the lead foil dosage, the cupel type, cupellation loss, the addition amount of silver, and the analytical lines on the determination results were discussed. The results showed that the matrix components including nickel and copper in 5 g of high nickel matte sample could be fully dissolved with 80 mL hydrochloric acid. The residue was collected with 0.45 μm membrane and then wrapped in 6.0 g of lead foil after adding 5 mg of silver. The cupellation was conducted in magnesia cupel at 950 ℃. Lead and few sulfides of base metals were oxidized and separated without loss of gold, platinum, and palladium. The formed silver granule was decomposed with mixed acid. Silver was separated in the form of silver chloride precipitate and had no interference with the determination. In the medium of aqua regia (1+9), the contents of gold, platinum, and palladium were determined by ICP-AES using Au 267.595 nm, Pt 265.945 nm and Pd 340.458 nm as the analytical lines. The correlation coefficients of calibration curves of elements were all greater than 0.999. The limits of detection for gold, platinum, and palladium were 0.067 μg/g(Au),0.085 μg/g(Pt) and 0.107 μg/g(Pd), respectively. The proposed method was applied for the determination of gold, platinum, and palladium in high nickel matte. The relative standard deviations (RSD, n=7) of determination results were between 2.8% and 5.9%. The found results were basically consistent with those obtained by the industrial standard method (YS/T 252.8-2020).