HIGH PERFORMING Al2O3-SiC-C MONOLITHIC REFRACTORIES RELEASING NO HYDROGEN FOR BF CASTHOUSE APPLICATIONS

Hydrogen Free Black Castables (ie, HFBC) have been designed for eradicating the safety risk due to hydrogen formation during installation in blast furnace troughs. They contain no metallic component so that no hydrolysis reaction generates hydrogen during curing. Comparison of several characteristics, ie, cold physical properties, drying aptitude, oxidation and corrosion resistance, between the HFBC and the ULCC versions of a 25%2SiC containing castable are presented. Flowing properties of HFBC leads to an optimal placement under vibration with no risk of voids formation and lamination during installation in a BF runner. Based on gas permeability and strength development considerations, drying as fast as a conventional ULCC castable releasing hydrogen is expected. The castable presents also much better resistance to cracking when applied on a hot surface. HFBC develops low mechanical strength after sintering, leading to advantages in term of wreak-ability and consequently to a lower consumption of non-corroded lining during runner cleaning. The sensitivity to carbon oxidation is also reduced mainly because of the oxidation inhibitor system. Finally, the results point out that the HFBC resistance to corrosion is better, leading to expect an improvement of lifetime during operation.