Improvements on corrosion behaviours of MgO–spinel composite refractories by addition of ZrSiO4

Corrosion behaviours of MgO–spinel–ZrSiO4 compositions were investigated. The influence of corrosion resistance based on the microstructural changes occurred due to the solubilities of constituents in corroded regions was examined using SEM/EDX analysis. The following observations were determined by microstructural characterisation performed at the interface of clinker–refractory: (i) the formation of ZrO2 and Mg2SiO4 phases among MgO grains after sintering, (ii) the formation of CaZrO3 phase during penetration, (iii) prevention of penetration by new phases formed making a barrier effect against clinker with an improvement in densification, and (iv) the decrease in the amount of CaO and the increase in the quantity of MgO using EDX analysis made moving from clinker towards refractory. The addition of ZrSiO4 reduced the values of penetration and spreading areas of the corroded regions of composite refractories and improved the corrosion resistance significantly, leading to a long service life of MgO–spinel–zircon based refractories for industrial applications.