Determination of Total Iron in Pellet by Titanium Trichloride Reduction and Potassium Dichromate Titration

The sample was treated with alkali mixed flux fusion,dissolved with hot water and hydrochloric acid.The Fe3+ was reduced to Fe2+ by stannous chloride-titanium trichloride with sodium tungstate as indicator to indicate the end.In the H2SO4-H3PO4 medium,the total iron in pellet was titrated by potassium dichromate standard solution with sodium diphenylamine sulfonate as indicator.The absolute error of determination TFe is less than 0.15%,avoiding introduced error by using potassium dichromate oxidation for fading tungsten blue.