Study of the refractory used in a submerged arc furnace in the copper-making industry

A cost driver in the copper-making industry is the periodical relining of the furnaces because of wear. This paper presents thermochemical calculations (using the FactSage (TM) database) focused on the evaluation of the slag-refractory chemical interaction in a submerged arc furnace (SAF) used for slag-cleaning operations. This evaluation was made under different conditions: slag-refractory volume ratio, oxygen partial pressure, and different types of slag. The new phases formed as a consequence of the slag-refractory chemical interaction were identified and quantified. To support the theoretical calculations based on thermochemistry, a postmortem study was carried out on a SAF used at the Atlantic Copper Smelter (Spain) after a 6-year campaign (4.5 mill. t. slag processed). Refractory samples were taken from different locations on the wall and analyzed using a scanning electron microscope equipped with an Energy Dispersive Spectroscopy system.