硫酸亚铁铵滴定法测定合金铸铁中Cr含量

Determination of Cr Content in Alloyed Cast Iron with Ammonium Ferrous Sulfate Titration

介绍了硫酸亚铁铵滴定法测定合金铸铁中Cr含量的试验方法,分析了硫酸用量、磷酸用量、氧化时溶液体积、过硫酸铵用量、硝酸银用量的影响,以及共存元素Fe、Mn、Ni、Mo、Co、Ce、W、V的干扰作用。试验选用硫酸8 mL、磷酸2mL、氧化时溶液体积120 mL、过硫酸铵10 mL、硝酸银5 mL,结果显示:采用硫酸亚铁铵滴定法测定合金铸铁中Cr含量的方法操作简便,准确度高,稳定性、再现性好,同时可避免溶液中大量的W、V等元素对Cr含量测定的干扰。

The test method of using ammonium ferrous sulfate titration to determine Cr content in alloyed cast iron was introduced.The influences of sulphuric acid dosage,phosphoric acid dosage,solution volume during oxidation,ammonium persulfate dosage,silver nitrate dosage,and,as well as,the interference effect of the coexisting elements Fe,Mn,Ni,Mo,Co,Ce,W,V were analyzed.For the test,8 mL sulphuric acid and 2 mL phosphoric acid were used,solution volume during oxidation was 120 mL,ammonium persulfate was 10 mL,and silver nitrate was 5 mL.The result showed:using ammonium ferrous sulfate titration to determine Cr content in alloyed cast iron was a method with simple operation,high accuracy and good repeatability,and moreover,it could avoid the interference of W,V and other elements on the determination of Cr content.