A novel procedure for the evaluation of new refractories for aluminium furnaces

Abstract

Refractory materials for aluminium industry are designed to be resistant to different degrees of thermal, mechanical and chemical wear. The refractory wall thickness reduction during service life increases the heat losses through walls, decreasing the thermal efficiency of the furnace. Last developments are focused on obtaining refractories with better performance and improved insulation properties. On this regard, a novel procedure has been developed to compare the thermal and chemical performance of different refractories. This procedure includes comparing the resistance of the refractory to molten aluminium, determining corundum and cracks appearance, and measuring the internal and external wall temperatures of a testing furnace using thermography. These temperature measurements make possible to estimate the wall thermal conductivity together with its evolution in time and also validate its simulation modelling in order to be used in future furnace designs. Two refractories have been tested by this procedure for comparative purposes; a commercial alumina castable and an improved alumina castable with better insulation properties