Alteration analysis of refractories bricks for industrial horizontal anodes baking furnace

Abstract

Abstract This study highlights the alteration of refractory bricks for anode baking furnace for unused and used bricks after 96 baking cycles. The chemical composition of the unused bricks included silica (51.37wt.%) and alumina (34.05wt.%). A decrease of compressive strength from 48.45 MPa to 32 MPa respectively for unused and used bricks were observed. The bulk density obtained by mercury intrusion porosimeter method decreased from 2.48 to 2.38 g/cm3for unused and used bricks; while the bulk density by archimades method increased from 2.29 to 2.49 g/cm3. The water absorption by Archimedes method is decreased from 6.65wt.% to 5.05wt.%. While the total porosity obtained by mercury intrusion porosimeter increased from 15.41wt.% to 17.21wt.% for unused and used bricks. In the same way the total cumulative pore increased from 62.05 mm3/g to 72.35 mm3/g for unused and used brick. While the average pore radius decreased from 5.65 µm to 1.06 µm respectively for unused and used brick due to the deposition of C and particles inside the pores. The alteration of the hot side of brick is due by the decrease of Si and Ti with increase of Fe; while the alteration of anode side is due to the increase of Si and decrease of Al. The anode side of brick is deterioted rapidly than hot side of brick. Mullite peak seems to be not change, suggesting that a very compacted brick with high mullite content and high alumina content 75-90wt.% seems to be the best matrix for bricks in anode baking furnace.