过硫酸铵氧化-硫酸亚铁铵滴定法测定火法冶炼镍基体料中铬含量

Determination of Chromium in Nickel-bearing Matrix Material Obtained by Pyrometallugy-Oxidation with Ammonium Persulfate and Titration with Ferrous Ammonium Sulfate

应用过硫酸铵氧化硫酸亚铁铵滴定法测定了火法冶炼镍基体料中铬的含量。试验证明：用盐酸、硝酸及少量氢氟酸溶解，并经硫酸一磷酸混合酸冒烟处理可达到试样中铬的完全溶解。应用所提出的方法分析了3个标准样品，所测得铬量与认定值相符。另取6个镍基体料样品分别进行11次独立测定，测定结果的相对标准偏差在0．76％～2．0％之间。

The method of oxidation with （ N H4 ） 2 S2O8 and titration with （NH4） 2 Fe（SO4）2 solution as t itrant was applied to the determination of chromium in nickel bearing matrix material obtained by pyrometallurgy. It was shown that complete dissolution of the sample, including its componental chromium, was accomplished by treating with HCI, HNO3 and few drops of HF, and followed by fuming with mixed acid of H2SO4-H3PO4. The proposed method was used in the analysis of 3 standard samples, giving results of Cr-eontents in consistency with the certified values. 6 samples of the Ni-bearing matrix material were taken and 11 determinations of their Cr contents were carried out by this method, values of RSD＇s found were in the range from 0. 76% to 2.0%.