岩石矿物及粉尘中游离二氧化硅的测定

The Determination of Free-SiO_2 in Rocks, Minerals and Dusts

摘要: 改进了游离二氧化硅（fSiO2)测定中试样的分解方法，采用硫－磷混酸替代单独使用磷酸分解试样，防止了焦磷酸盐的形成，同时，氟硼酸对fSiO2的溶解率符合测定要求。改进的方法用于标准物质中fSiO2的测定，结果与标准值或磷酸溶矿重量法相符。对于ω(fSiO2)=3.26%的标样10次测定的RSD为2．4％。

Abstract: The sample decomposition method in analysis of free SiO 2 in rocks, minerals and dusts was improved. Sulphuric phosphoric mixed acid was used instead of phosphoric acid alone to avoid the formation of pyrophosphates. And the solubility of free SiO 2