氟硅酸钾滴定法测定铬矿中二氧化硅

来源期刊：冶金分析2010年第9期

论文作者：戚淑芳 邴一宏 张杰 王隽

文章页码：74 - 76

关键词：铬矿； 二氧化硅； 低温亚熔； 氟硅酸钾滴定法

Key words：chromium ore； silicon dioxide； low temperature sub-molten； potassium fluosilicate titrimetry

摘    要：提出了采用KOH或KOH-KNO₃低温亚熔盐法分解铬矿,用氟硅酸钾滴定法测定其中二氧化硅的方法。本方法消除了Al₂O₃及MgO的共沉淀干扰,同时避免了过氧化钠对坩埚材料的严重腐蚀,坩埚使用寿命比用过氧化钠高温熔融时提高了10倍以上。用自制的带塑料抽滤器的抽滤瓶抽滤沉淀物,速度快,残余酸易洗涤、中和,无漏滤现象。方法用于铬矿中二氧化硅的测定,相对标准偏差(RSD)小于1.3%,回收率为98%～101%。

Abstract: Decomposing the chromium ore by KOH or KOH-KNO₃ low temperature sub-molten salt method,silicon dioxide in it was determined by potassium fluoride titrimetry.This method not only eliminated the interference of the co-precipitation formed by Al₂O₃ and MgO,while avoiding the severe corrosion to the crucible material by introducing the sodium peroxide,but also improved the service life of crucible by more than 10 times in comparison with sodium peroxide fusion method.A self-made filter flask with a plastic pump device was adopted,which has such advantages as: fast and easy to filtrate and wash and neutralize acid,leak-free.This method has been applied to determine SiO₂ in chromium ore with relative standard deviation (RSD) less than 1.3%,and recoveries of 98%-101%.