硅钼蓝光度法测定萤石及其精矿中二氧化硅的含量  

Silicon-molybdenum blue spectrophotometric determination of silica in fluorite and its concentrate

作　　者：杨朝帅[1] 周建辉[1] 孔幸花[1] 孙静 

机构地区：[1]河北省地勘局唐山实验测试所,河北唐山063000 [2]唐山钢铁集团炼铁厂化验室,河北唐山063000

出　　处：《冶金分析》2012年第7期59-62,共4页Metallurgical Analysis

摘　　要：提出硅钼蓝分光光度法测定萤石块矿及其精矿中不同含量范围内二氧化硅的改进方法。以氢氧化钠作为熔剂,样品的熔融在银坩埚内进行,以避免使用昂贵的铂坩埚及造成其损坏;优化了待测试液制备操作过程,通过采用返酸化法制备试液提高试液的稳定性;用三氯化铝替代具有缓冲作用的硼酸,消除溶液中过量的氟元素对测定的影响;操作全程避免玻璃器皿中二氧化硅的引入;改变标准溶液的酸化方式,校准曲线在50～1 000μg范围内线性相关系数r≥0.999 7。经对五种不同二氧化硅含量的萤石标准样品进行分析比较,本法的测定结果与认定值及HF挥散重量法的测定值相一致,相对标准偏差均小于0.5%。经t检验法验证,测定结果同认定值之间不存在显著性差异。改进后的方法显色体系简单,可测定萤石中62.00%以内的二氧化硅含量。The paper proposed an improved way of silicon-molybdenum blue spectrophotometric method which has been used in the determination of silica content within different ranges in fluorite and concentrate.Using sodium hydroxide as flux,the sample was melted in silver crucibles instead of expensive platinum crucible.The sample solution preparation process was optimized by using back-acidification method to improve the stability of the sample solution.Using aluminium trichloride to replace boric acid which has buffer effect to remove the interference of excessive fluorine with the solution,and the introduction of the silica in glassware was avoided during the whole operation.The way of acidification for the standard solution was changed.The calibration curve was linear in the range of 50-1 000 μg,r≥0.999 7.By analyzing and comparing the five fluorite standard samples with different content of SiO2,the results of this method were consistent with the certified values of the standard samples and the found values of HF evaporation gravimetric method.All of the relative standard deviations were less than 0.5 %.Through verification by the ＂ t-Test ＂,there was no significant difference between the results of this method and the certified values of the standard samples.This improved method has simple chromogenic system.It can be used for analyzing fluorite containing no more than 62.00 % SiO2.

关 键 词：萤石矿 二氧化硅 硅钼蓝 分光光度法 

分 类 号：P575.4[天文地球—矿物学] O657.3[天文地球—地质学]