Cathodoluminescence microscopy characterization of chrome-free refractories for copper smelting and converting furnaces

The results of an experimental program assessing the potential of several c hrome-free refractory materials as potential replacements for the mag-chrom e brick currently used in copper production furnaces are presented. Several commercial chrome-free bricks were subjected to the standard dip test in a high-copper calcium ferrite slag. The mineralogical changes in the bricks resulting from their interaction with the molten slag are described. The us e of optical cathodoluminescence microscopy as an analytical tool is highli ghted, along with reflected light microscopy and scanning electron microsco py-energy dispersive spectroscopy. Using the three tools together provides a description of the experimental results not achievable using one or two a lone. The penetration resistance of the potential replacement refractories is comparable to that of mag-chrome, but the substitution of Fe2+ for Mg2in the periclase and spinel crystalline structures of the replacements redu ces their corrosion resistance compared with mag-chrome, diminishing the li kelihood that they will serve as reliable alternatives.