Interactions of Cr₂O₃–Al₂O₃–ZrO₂ refractory with slags in an entrained-flow coal-water slurry gasifier

The corroded microstructures of the Cr₂O₃–Al₂O₃–ZrO₂ refractory brick in an industrial opposed multi-burner (OMB) coal water slurry gasifier were investigated. It was found that the chromite spinel isolation layer rich in iron and magnesium was formed on the surface of the corroded brick body. By comparing and analyzing the corrosion of different zones in the gasifier, the results indicated that the molten slag entered the brick through the gaps and generated the spinel layer along the edge of the gaps, causing the dense structures of the refractory surface destroyed. In addition, in the high chrome brick corrosion experiment conducted by HTSM, 3 μm sized spinel were observed covering on the surface. The FactSage calculation results showed that the amount of spinel produced would drop significantly as the slag penetrated.