Determination of total iron in ferroboron by potassium dichromate titrimetric method
WANG Su-mei1, 2, WANG Dong-jie1, 2, ZHANG Yi-ming1, 2, HAO Qian1, 2
1. National Engineering Research Centre of Rare Earth Metallurgy and Function Materials, Baotou 014030, China; 2.Baotou Research Institute of Rare Earths, Baotou 014030, China
Abstract：After the sample was melted and decomposed by mixed flux of sodium hydroxide and sodium peroxide, the fusion sample was leached with hot water and acidized by 30 mL HNO3(1+1). Then sulfuric acid and phosphorus acid were added to eliminate nitrogen oxide and hydrogen peroxide. After the sample was further extracted by hydrochloric acid, stannous chloride was first added to reduce the majority of ferric iron into ferrous, then 7 drops of 15 g/L titanium trichloride solution was added until the solution turn blue in order to reduce the residue ferric iron into ferrous. Simultaneously, the impact of excess titanium trichloride was eliminated by the fading of tungsten blue oxidized by potassium dichromate. Finally, total iron in the sample solution was titrated by potassium dichromate standard titration solution with sodium diphenylamine as indicator to realize the determination of total iron in boron ferroalloy. Experiment indicated that the coexistence elements in ferroboron had no interference with the determination of total iron. The method was applied to determination of total iron in ferroboron certified reference materials. The results were conformed to the certified values, and the relative standard deviations (RSD, n=7) was smaller than 0.5%.
王素梅, 王东杰, 张翼明, 郝 茜. 重铬酸钾滴定法测定硼铁合金中全铁[J]. 冶金分析, 2014, 34(6): 68-70.
WANG Su-mei, WANG Dong-jie, ZHANG Yi-ming, HAO Qian. Determination of total iron in ferroboron by potassium dichromate titrimetric method. , 2014, 34(6): 68-70.
