Investigation of properties of boehmitic sol coated graphite added alumina-low cement castables

In this study, benefiting from the low wettability of graphite, various amounts were added to low cement alumina castables to investigate the resistance of refractories to slag corrosion. For this purpose, typically flake graphite was coated with alumina by a sol-gel method and then added to a mixture of the refractory in various amounts. After the physicomechanical investigation, steel ladle slag with a basicity ratio of 2.29 was charged into the crucibles which were prepared according to DIN 51069 standard. After the beat treatment, samples were cut vertically, for investigation. For macroscopic analysis, images taken from the slag-refractory surfaces were digitized and subjected to image analyses to investigate the penetration of the slag. Microscopic analyses were carried out with SEM-EDS to determine the elemental dispersion at the refractory-slag interaction zone. Experimental results indicate that the alumina coated graphite addition give improved slag corrosion resistance of alumina castables.