Comparison of corrosion behavior of primary/modified nickel slag with semi-rebonded periclase-chromite refractory

Abstract

Semi-rebonded periclase-chromite refractories are commonly utilized in the working lining section of the molten pool in oxygen-enriched top-blowing furnaces for nickel production. Its resistance to nickel slag corrosion determines the safety and service life of the melting furnace. The composition of nickel slag influences the corrosion resistance of semi-rebonded periclase-chromite refractories. By comparing and analyzing specimens corroded by primary and modified nickel slag, the influence mechanism of w(CaO)/w(SiO₂) variations on corrosion resistance of semi-rebonded periclase-chromite refractories was clarified. The results show that a spinel isolation layer is preferred to form at a lower w(CaO)/w(SiO₂) ratio (< 0.576) and enhance the corrosion resistance of semi-rebonded periclase-chromite refractories. As the ratio increases, the slag viscosity falls and the corrosion products contain larger levels of Ca₃Cr₂Si₃O₁₂ and Ca₃MgSi₂O₈, which prevent the creation of the isolation layer and establish a conduit for Ca²⁺ and Si⁴⁺ transport and reaction into the interior of the refractory.