Investigations into refractory wear at Cerro Matoso SA

Cerro Matoso S.A. (CMSA) would like to improve the performance of the elect ric furnace refractories, particularly below the coolers at the slag/metal interface. Hatch Associates was contacted to investigate the mechanism of r efractory erosion and evaluate various refractory products for their potent ial use in the furnace. In the present paper, a fundamental approach was ta ken to understand the mechanisms of refractory wear in the furnace. A comprehensive brick selection strategy involves the consideration of mech anical, thermal and chemical aspects of lining exposure. This paper focusse s on characterization of relevant aspects of the process and attempting to obtain a deeper understanding of the mechanism of wear experienced in the f urnace. Physical, chemical and thermodynamic analysis of the slag were conducted in order to understand the effects on the refractory lining. A hypothesis of the controlling wear mechanism in the furnace involving the slag's formidab le wetting properties, attack of the calcium silicate aggregate bonds, and the capacity to dissolve MgO is presented Analysis of samples removed from the furnace in addition to the laboratory experiments led to the conclusion that the controlling mechanism of wear be low the minimum metal level in the furnace is chemical in nature. From this conclusion, the emphasis of the selection process was concentrated on bric ks that provide the greatest resistance to chemical attack.