Periclase-Chromite Refractory Decomposition by a Coal – Gas Medium During Copper Sulfide Raw Material Processing

The composition and structure of periclase-chromite refractories contacting the coal–gas atmosphere of copper-sulfide-ore smelting furnaces were studied. Combined effects of high-temperature suspensions of enriched copper concentrate and SO2 altered the chemical composition of the refractory surface and inner layers. The impurity contents (wt%) reached Fe 54.0, Cu 7.2, Zn 6.4, and S 1.8. Saturation of the surface layer with iron and nonferrous-metal oxides decreased its porosity and promoted the formation of low-melting compounds and eutectics. The periclase-chromite refractories were decomposed by exfoliation of layers with filled pores during alternating heat—cool cycles because of the different linear thermal expansion coefficients of the phases. The surface layer of spent refractories should be mechanically removed for recycling. The remaining part is suitable for producing refractory powders for various purposes.