Effect coal ash on some refractory properties of alumino-silicate (Kankara) clay for furnace lining

The work aimed on the improving the refractory properties of Kankara clay (alumino-silicate) found in Kankara Village, Katsina State, Nigeria by blending with coal ash for the production of refractory bricks was investigated. Coal ash additions were varied from 5 to 25 wt% in the blend. Refractory properties such as: linear shrinkage, apparent porosity, bulk density, cold crushing strength and thermal shock resistance were tested. The results were compared with standard refractory properties for fireclay bricks. All the values obtained from the blends are within the recommended values for medium fireclay bricks. Hence, addition of coal ash to Kankara clay enhanced the refractory properties; the bricks were used in the production of heat treatment furnace with good thermal resistance.