Corrosion resistance of Al-Cr-slag containing chromium-corundum refractories to slags with different basicity

Al-Cr slag is the solid waste generated by the smelting of Cr metal. It presents a range of environmental hazards. This study addressed the corrosion resistance of Al-Cr slag containing chromium-corundum refractories to slags with different basicity. Herein, we provide suggestions for the use of Cr-corundum of different basicity in kilns. Al-Cr slag, brown fused Al2O3, and chrome green were used as the raw materials, with pure calcium aluminate cement being used as a binder. The brick samples, prepared using different blends of chrome green and corundum, were fired at 1600 °C, and subsequently subjected to a slag corrosion test. After corrosion by slag of different basicity, the phase composition and microstructure of the sample were analyzed by X-ray diffraction, energy dispersive spectrometer and scanning electron microscopy. There were two major findings. First, Cr-corundum brick made from Al-Cr slag has a better slag corrosion resistance than that made from Cr2O3 and brown fused Al2O3. Second, Cr-corundum brick made from Al-Cr slag has superior corrosion resistance to slag with a CaO:SiO2 ratio of 2:1.