Degradation Mechanism of Magnesia-Chrome Refractory in Copper Making

Direct Bonded Mag-Chrome Refractories have been extensively used in copper making. The integrity of furnace linings in copper production is crucial for better productivity and quality but, with increasing impurity levels in primary raw material and use of secondary scrape are influencing lifespan of the refractory materials. To get a better refractories performance, continuous research is required to understand the corrosion mechanism. Post-mortem analysis of the used refractories and lab scale simulation are very much essential to understand the degradation mechanism of the refractory materials. In this study, Magnesia chrome bricks were collected from different type of furnaces. These bricks were physically examined and infiltration depth of Cu-Cu₂O and slag inside the bricks were studied. The chemical, thermal, and mechanical stresses that degrade refractory linings have been identified through X-ray diffraction, Scanning Electron Microscopy/Energy-Dispersive X-ray Spectroscopy, X-ray fluorescence methods. The effects of temperature and fayalite slag on infiltration depth and microstructural evolution in the matrix was also studied. The outcome of the post-mortem study and the lab scale simulation tests allowed a more comprehensive understanding of the degradation mechanism and help us to design more performance-oriented refractories.