Determination of silver in platinum-palladium concentrate by potassium thiocyanate titration with lead fire assay
HUANG Yajuan, LIU Fangmei*, GAN Cong, HUANG Chunyan
Zijin Copper Co.,Ltd.,FuJian Key Laboratory for Green Production of Copper and Comprehensive Utilization of Associated Resources,Shanghang 364204, China
Abstract：The accurate determination of silver in platinum-palladium concentrate has important guiding significance for its efficient and comprehensive utilization. However, the content of silver in platinum-palladium concentrate is high, and the matrix is complex, leading to high difficulty in determination. Silver in sample was preconcentrated with lead fire assay, and the loss of silver in cupellation was avoided by remaining lead cupellation. Then the lead beads were dissolved with nitric acid. Palladium was separated by dimethylglyoxime precipitation method, thus eliminating the interference of palladium with the titration end point color. Finally, silver was titrated with potassium thiocyanate titration. Consequently, a method for determination of silver in platinum-palladium concentrate was established by potassium thiocyanate titration combined with lead fire assay. The experimental results showed that the loss of silver could be reduced when the remaining lead in cupellation was 2-3 g after preconcentrating silver via lead fire assay. After lead beads was digested with 4 mol/L nitric acid and palladium was separated with 36 mL of dimethylglyoxime ethanol solution, the interference of palladium with the determination could be effectively eliminated. The content of silver in actual samples and simulated samples of platinum-palladium concentrate were determined according to the proposed method. For the actual sample, the relative standard deviations (RSD, n=7) of the results were between 0.50% and 0.72%, and the recoveries were between 96% and 101%. For the simulated samples, the results were consist with the theoretical values.
黄雅娟, 刘芳美, 甘聪, 黄春燕. 铅试金-硫氰酸钾滴定法测定铂钯精矿中银[J]. 冶金分析, 2022, 42(12): 60-65.
HUANG Yajuan, LIU Fangmei, GAN Cong, HUANG Chunyan. Determination of silver in platinum-palladium concentrate by potassium thiocyanate titration with lead fire assay. , 2022, 42(12): 60-65.
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