PREPARATION OF FINE PARTICLE CHROMITES - A COMBUSTION APPROACH

Fine particle metal chromites, MCr2O4 where M = Mg, Mn, Fe, Co, Ni, Cu and Zn have been obtained by the combustion of a redox mixture containing corresponding divalent metal nitrate, chromium (III) nitrate and tetraformal trisazine (TFTA). An aqueous saturated solution of the redox mixture when rapidly heated at 350°C boils, foams and ignites to yield voluminous, fine particle chromite powder. Formation of chromite was confirmed by X-ray diffraction pattern and IR spectra. Fine particle nature of chromites was studied using particle size analysis, surface area measurements, TEM and SEM. The particle size of chromites is below lum and the surface area ranges from 13 to 30 m2/g. © 1990.