重铀酸盐是核燃料循环的重要原料,对杂质含量要求严格,其中二氧化硅的含量是检验产品是否合格的一项重要指标。本工作采用硅钼蓝分光光度法对重铀酸盐中二氧化硅含量进行了测定。方法原理是低酸条件下氟离子与硅酸根反应生成氟硅酸,氟硅酸与钼酸铵生成硅钼黄杂多酸络离子,用亚铁将硅钼黄 Heavy uranate is an important raw material for nuclear fuel cycle, the content of impurities demanding, including silica content is to test whether the product is an important indicator of eligibility. In this work, silica molybdenum blue spectrophotometry was used to determine the content of silica in the heavy uranate. The principle of the method is that fluoride ions react with silicate to form fluorosilicic acid under low acid conditions, and fluorosilicic acid and ammonium molybdate generate silicon molybdenum yellow heteropoly acid complex ions, and ferrous silicon molybdenum yellow