Post-mortem study of magnesia-chromite refractory used in Peirce-Smith Converter for copper-making process, supported by thermochemical calculations

A cost driver in copper production is the periodical relining of the furnaces because of wear. This paper presents a post-mortem study carried out in a Peirce-Smith Converter (PSC). Samples taken from different locations after a 250-batch campaign at Atlantic Copper (Spain) were analyzed. New phases are generated as a result of the chemical interaction between the molten phases of the bath and the refractory, creating a reaction layer on the hot face of the refractory. This layer has properties that differ from the refractory, so spallation occurs due to mechanical and thermal shocks during operation. Thermochemical calculations were carried out to support the post-mortem study. An evaluation was made of the chemical interaction between the molten phases and the refractory under different conditions (slag-refractory volume ratio and Fe/SiO2 ratio in slag). The solidus and liquidus of the new phases, the amount and composition of the spinel and olivine formed, and the density increase of the refractory in the reaction layer were also determined.