Magnesite crucibles for use in high frequency induction furnace

Crucibles used in high frequency induction furnaces have to withstand wide variations and sudden fluctuations of temperature. Magnesite crucibles are preferred because of their resistance to basic slags inspite of poor spalling resistance. A study was made to evolve suitable compositions and techniques for the production of crucibles capable of withstanding severe service conditions. It was found that proper control of the composition, grain size and firing temperature are important factors that deserve consideration in the fabrication of such crucibles. (R.K. Rao, Senior Scientific Officer, P.C. Sen, Junior Scientific Officer and H.V. Bhaskar Rao, Assistant Director, National Metallurgical Laboratory)