Rapid indirect volumetric method for determination of silicon in ferro-silicon

Abstract

It was observed from the results of analysis of different grades of ferro-silicon during its production in NML submerged arc-furnace that the total of iron and silicon comes to 98%, remaining 2% being aluminium, calcium, magnesium, manganese, phosphorous, carbon etc. Indirect volumeric method for determination of silicon in ferro-silicon was based on the above observation. The percentage of iron was determined volumetrically after decomposing the sample in ordinary glass beakers with nitric acid and hydrofluoric acid and fuming with sulphuric or perchloric acid and the silicon content was obtained by deducting it from the observed total of iron and silicon, i.e., 98. Results of silicon by this method agree favourably with those of conventional methods. Method is very rapid and simple and does not require any costly platinum basins or chemicals. The silicon can be determined within half an hour when done in batches. (Shri S.N. Jha, Scientist, Shri A.C. Biswas, Scientist, Dr. H.P. Bhattacharya, Scientist; National Metallurgical Laboratory)