氯氧镁胶凝材料中总氯离子的测定:(Ⅱ)分析方法的比较与评价

摘要

氯氧镁胶凝材料中的总Cl-含量是衡量产品吸潮、返卤和泛霜性能的关键指标之一.分别用重量法、CNS14164方法以及用甘油保护沉淀和过滤分离沉淀的Volhard法测定了5个MOC样品中的总Cl-含量；并以重量法的测定结果为基准,比较和评价了其余3种分析方法.结果表明,CNS 14164方法主要由沉淀转化引起负误差,该方法受随机误差的影响较大；用甘油保护沉淀后,测定的精密度和准确度提高,测定结果的相对误差为-0.24％,该方法可替代CNS14164方法；过滤分离沉淀后,分析结果受随机误差的影响较小,但该方法存在较大的系统误差,测定结果的相对误差为1.43％.%Chloride ion(Cl- ) content is one of the key indicators of deliquescence, dehalogenation and efflorescence in the Magnesium Oxychloride Cement(MOC). In this work,the Cl" content in MOC was detecting by four methods: gravimetric method and volhard method for no-isolating and no-filtering, isolating by glycerol and filtering of AgCl. Comparisons of results obtained by the three different methods of volhard method with those obtained by the gravimetric method of Cl" were carried out for five MOC specimens from factory. As it turned out, the no-isolating and no-filtering method had the worst precision and accuracy , the isolating method had the smallest relative error which would take the place of the titrimetric method in standard of CNS 14164, the filtering method had the largest relative error because of the system error.