重铬酸钾测铁的方法比较及其环境经济效应

对K2Cr2O7测定水泥生料中铁的还原剂SnCl2-HgCl2、SnCl2-TiCl3、锌粉以及铝片进行了分析和比较。结果表明,采用铝片作还原剂没有汞盐等重金属的污染,且该方法操作简单,结果可靠,成本低廉,适用于生产部门的常规检测和量大面广的实验,是一种绿色的化学检测方法。

Comparative Study of the Methods for Determination of Iron by Potassium Dichromate Titration and the Evaluation of Their Economic and Environmental Effects

For the determination of the iron contents in cement raw meal,the potassium dichromate titration is a usual method.In this process,some reducing agents,such as SnCl2-HgCl2,SnCl2-TiCl3,Zn powder or Al flake,are often used to reduce Fe3+ ion into Fe2+ ion before the titration step.Herein,we evaluate these four reducing agents from the points of environment and economy.The results show that the utilization of Al flake as reducing agent is a relatively simple,accurate and cost-effective method.More importantly,the method can avoid the pollution of mercury salt wastewater as compared to the classical SnCl2-HgCl2 method.Furthermore,this environment-friendly detection method is suitable for the routine test of factory departments and the enormous basic chemical experimental teaching.