软锰矿中MnO_(2)、MnO及Fe_(2)O_(3)的微量分析法

Microanalysis of MnO_(2),MnO and Fe_(2)O_(3)in Pyrolusite

软锰矿(MnO_(2))分析常要求测定MnO_(2)、MnO_(2)及Fe_(2)O_(3)等项目。MnO_(2)以往多用草酸钠还原法测定。

An indirect method for the microanalysis of MnO_(2),MnO and Fe_(2)O_(3)has been developed,the pyrolusite is reduced with Na_(2)C_(2)O_(4),and the excess Na_(2)C_(2)O_(4)is oxidized with excess K_(2)Cr_(2)O_(7),using Mn^(2+)as catalyst.The excess K_(2)Cr_(2)O_(7)is determined spectrophotometrically.MnO_(2)is obtained by calculation.MnO_(2),MnO and Fe_(2)O_(3)can be determined in a 5 milligram sample with satisfactory results.