萤石中二氧化硅和氟化钙的系统分析

来源期刊：冶金分析2010年第10期

论文作者：宋新艳

文章页码：58 - 61

关键词：萤石； 二氧化硅； 氟化钙； 分光光度法； EDTA滴定法

Key words：fluorite； silicon dioxide； calcium fluoride； spectrophotometry； EDTA titrimetry

摘    要：萤石试样以过氧化钠为熔剂,于铁坩埚内进行快速熔融,熔块以含硼酸的热水溶液浸取,盐酸溶解试样,制成母液。以硅钼蓝分光光度法测定二氧化硅含量,以EDTA滴定法测定总钙量,单独测定CaCO₃的量用以校正总钙量从而得到CaF₂含量。以硼酸消除氟的干扰,以三乙醇胺掩蔽Fe³⁺、Al³⁺,并以同品种的标准样品绘作校准曲线和采用标准样品换算的方法对数据进行处理。本方法用于萤石标准样品中SiO₂,CaF₂的测定,相对标准偏差分别为4.5%和1.7%,测定值与认定值一致,t检验合格。方法适用于工厂实验室的日常分析。

Abstract: The fluorite sample was rapidly melted in an iron crucible using sodium peroxide as flux.The fusion cake was leached with hot water containing boric acid.The sample was then dissolved with hydrochloric acid to prepare the mother solution.The content of silicon dioxide and total calcium were determined by silicomolybdic blue spectrophotometry and EDTA titrimetry,respectively.The amount of CaCO₃ was singly determined to correct the total calcium and calculate the content of calcium fluoride.The interference of fluorine was eliminated by boric acid,and Fe³⁺ and Al³⁺ were masked by triethanolamine.The calibration curve was plotted with the same type of standard sample,and the data was processed using standard sample conversion method.The proposed method was applied to the determination of silicon dioxide and calcium fluoride in fluorite standard sample.The relative standard deviations (RSD) were 4.5% and 1.7%,respectively.The determination results were consistent with the certified values,and the t test was qualified.This method was applicable to the daily analysis in factory laboratories.