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镀铬液中硫酸根的含量对于镀铬层质量和电流效率有着显著的影响。所以快速测定镀铬液中硫酸根,较好地控制镀液中硫酸根的含量具有重要意义。硫酸根的测定通常用硫酸钡重量法、硫酸钡沉淀-EDTA滴定法、离心沉降法,前者速度太慢,后二种方法是对前法的改进,但分析精度和准确度都较差。近年来,对硫酸根的测定作过不少研究,提出了氢碘酸-次磷酸-盐酸混合试剂还原硫化铅光度法、苯甲酸银沉淀分离大量铬,EDTA滴定法、磷酸活性炭蒸馏碘量法、苯甲酸银分离铬,阳离子交换钡电极法、小型Al_2O_3柱-铅电极法等。但上述方法都有较繁琐的分离手续,有的还需要特殊的仪器设
The sulfate content in the chrome plating bath has a significant effect on the chrome plating quality and current efficiency. Therefore, the rapid determination of sulfate in chrome plating solution, the better control of sulfate content in the bath is of great significance. The determination of sulfate is usually used barium sulfate gravimetric method, barium sulfate precipitation-EDTA titration, centrifugal sedimentation method, the former is too slow, the latter two methods is to improve the former method, but the analysis accuracy and accuracy are poor. In recent years, many studies have been made on the determination of sulfate radical. Hydrazine iodide-hypophosphorous acid-hydrochloric acid mixed reagent was used to reduce lead sulfide photometric method. A large amount of chromium was precipitated by silver benzoate precipitation. EDTA titration method and phosphoric acid activated carbon distillation iodometry , Silver benzoate separation chromium, cation exchange barium electrode method, a small Al_2O_3 column - lead electrode method. However, these methods have more complicated separation procedures, and some also require special equipment