Corrosion Mechanism of Refractory Bricks Lining the Cement Kiln

Abstract

Present work investigates causes of damage of two types of refractories, the magnesite 80% MgO and high alumina > 70% Al2O3 lining kiln of ordinary Portland cement at the burning and lower transition zones respectively. To estimate degree of penetration of cement clinker during kiln operation, chemical analysis was conducted for bricks after use for a limited period of time ,and also for clinker before and after burning to eliminate detrimental corrosive materials (like alkalis, sulfur, chlorine). Measurements of corrosion with time were reported and an experimental test was conducted to study the alkali attack on high alumina and its effect on the thermo-mechanical –chemical corrosion. The results showed that alkali attack on alumina brick is the main factor of its damage. The damage of magnesite brick refers to peeling of clinker coating during the cooling of the kiln as well as the immigration of chromites from hot to cold face decreasing the toughness of the brick.