关键词: 微量硅, 硅钼蓝, 异戊醇, 萃取, 反萃

Abstract: For producing high-purity nickel material, silicon is one of the main impurities. To determine the trace silicon content is an exigent problem in industrial production. Test of heteromolybdate blue is the most popular method to analyze the silicon content, but for nickel sulfate solution, this method is limited because of color interference by Ni2+ ions. In this paper, the best conditions for the formation and extraction of heteromolybdate blue were studied. Iso-amyl alcohol was used as the extractant with a pH about 0.5 to extract heteromolybdate blue from nickel sulfate solution. Alkaline solution with pH over 12 was used as the stripping agent. Spectrophotometry was used to determine its absorbency after stripping. The experimental results showed that the absorbency had a good linear relation with the Si content. The analytic results are proved to be accurate, rapid and credible. The new analytical method can also expand to the silicon analysis of other colored solutions.

Key words: trace silicon, heteromolybdate blue, iso-amyl alcohol, extraction, stripping