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

Method of Detecting Chloride Ion in Magnesium Oxychloride Cement

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 ef- florescence in the Magnesium Oxychloride Cement（MOC）. In this work,the Cl- content in MOC was de- tecting by four methods：gravimetric method and volhard method for no-isolating and no-filtering,isolating by glycerol and filtering of AgCI. 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 accura- cy, the isolating method had the smallest relative error which would take the place of the titrimetric meth- od in standard of CNS 14164 ,the filtering method had the largest relative error because of the system er- ror.