Study on the Alumina - Silicon Carbide - Carbon Based Trough Castable

Abstract

Technological advancements in the iron and steel industries have changed significantly the operating practices of the blast furnace and to meet the challenges refractories are also getting changed and upgraded. Trough of blast furnace is important for transferring hot metal from blast furnace to transport vessel and the refractory lining of trough is subject to slag corrosion, oxidation, FeO corrosion from metal, abrasion and thermal / mechanical spalling etc. Trough refractories have changed from conventional hydrous clay‐based material to anhydrous mass to SiC containing material, to Al2O3–SiC based low‐cement castables. However, the presence of lime (cement) affects the high temperature properties and the performance of the refractory lining.
In the present work, Al2O3–SiC‐C based trough castable has been studied with both cement and sol bonding. Different particle size distribution of the castable was also studied. The study compares the various refractory properties of Al2O3–SiC‐C based trough castables, having different bonding system and flow behavior but with similar compositions. Also the effect of addition of spinel aggregates in the compositions with different bonding system was studied.
This comparative study showed improved dried strength for the cement containing compositions. Increasing amount of non‐oxide components (like graphite or SiC) resulted in reduced densification and strength properties for both the bonding system at all the processing temperatures. Increasing amount of spinel in the composition was found to improve the corrosion resistance and sol bonding was found to provide better corrosion resistances than cement bonding against blast furnace slag.