Performance Evaluation of Refractory Bricks produced from locally sourced Clay Materials
The performance evaluation of refractory bricks produced from some local clay deposits in Delta State, Nigeria was investigated. Four major sites in Delta State renowned for abundant clay deposits were selected, namely; Oghara, Ekpan, Ubeji and Jeddo. The clay samples were crushed, milled (pulverised) and sieved to produce very fine grains of less than 250 μm particle size distribution for all samples. They were then tested for shrinkage, bulk density, Loss on ignition , cold compression strength, apparent porosity, and thermal shock resistance. Also, their mineralogical composition and fusion temperatures were examined. The results shows that kaolin deposit at Oghara was found to be the best material suitable for the lining of the walls of most high thermally operated equipment as the expected operational temperatures of most of them are below 1200°C. It had a bulk density, porosity,cold compressive strength,shrinkage,loss of ignition,slag resisance of 1.74g/cm3 ,31.44%,100kg/cm2 ,5% and 12.18% respectively. Oghara clay was found to be less dense, contains more porosity, and possesses low iron content and higher refractoriness with fusion temperature above 1200°C. Ekpan clay is also suitable for medium thermal application in furnaces, kilns and stoves, while the rest could be beneficiated to improve on their insulating properties.
Keywords: Refractory bricks, clay material, performance evaluation, porosity, slag resistance.