氟硅酸钾沉淀-酸碱滴定法测定硅质耐火材料中二氧化硅

提出一种不用铂金坩埚和不需要用氢氟酸挥硅的氟硅酸钾沉淀 酸碱滴定法测定硅质耐火材料中SiO2含量方法，考察了检测的准确度和精确度，探讨了影响检测的干扰因素和可能的干扰机理。试样在银或者镍坩埚中，用氢氧化钠熔融，二氧化硅转化为硅酸钠，在有过量氯化钾存在的强酸性溶液中加入氟化钾溶液，生成氟硅酸钾沉淀，经过滤、洗涤后溶于沸水中，以酚酞为指示剂，NaOH标准溶液滴定水解后生成的氢氟酸。试样中SiO2的质量分数与Al2O3的质量分数比值大于或等于3.5时Al2O3对测定没有影响。应用本法检测硅质砂岩、硅砖等硅质耐火材料样品中的SiO2含量，测定值与认定值相符，且重复性较好。

Determination of silicon dioxide in siliceous refractory materials by potassium fluosilicate precipitation-acid base titration method

A determination method of silicon dioxide in siliceous refractory materials by potassium fluosilicate precipitation-acid-base titration method was established.Neither a platinum crucible nor the volatilization of silicon by hydrofluoric acid was needed.The determination accuracy and precision were investigated.The interference factors and possible interference mechanism were discussed.The samples were melted in a silver or nickel crucible with sodium hydroxide,during which the silicon dioxide in sample was ...