BigPatents India

The invention relates to unfired firebrick containing graphite which is intended for cement industry kilns and to the use of said firebrick in the aforementioned kilns in order to counteract the associated thermal and physicochemical deformation therein. The inventive brick composition contains between 75 and 62 wt.- % of magnesite (MgCO3), between 12 and 20 wt.- % of alumina (Al2O3) and between 4 and 11 wt.- % of graphite. Said composition also contains between 9 and 7 wt.- % of additives which are used to improve thermal shock resistance, thermal resistance and oxidation resistance (in a composition comprising aluminium powder, silicon metal, silicon carbide and clay) and between 3 and 4 wt.- % of resins. Said refractory material can be used to coat the inside of cement kilns in the high and low transition zones (4) as well as in the sintering zone (5). (FIG). 1