Rapid method for the complete analysis of ferro-chrome slag

A rapid method for complete analysis of ferro-chrome and silico-chrome slags using acid fluxes has been developed. In this procedure the finely powdered slag is decomposed by fuming with sulphuric acid and sodium sulphate at moderately high temperature. Silica is determined by hydrofluorisation from the residue and after fusion mixed oxides are precipitated from the filtrate. After determination of chromic oxide and ferric oxide in the mixed oxide alumina is determined by difference. From an aliquot of the filtrate left after precipitation of mixed oxides calcium oxide is determined by precipitating calcium oxalate and titrating with EDTA with murexide as indicator. Total calcium and magnesium oxides are determined from another aliquot with EDTA and solochrome black and magnesium is calculated by difference. It has been found that the method is suitable for routine complete analysis of ferro-chrome slags and two analysis can analyse four samples in one day. (Mr. A.C. Biswas, Scientist and Dr. H.P. Bhattacharyya, Scientist, National Metallurgical Laboratory, Jamshedpur)