Effects of Sawdust and Rice Husk Additives on Properties of Local Refractory Clay

--------------------------------------------------------------ABSTRACT------------------------------------------------------The effect of the addition of Sawdust and Rice husk to refractory clay on its properties was investigated. The clay sample was first analyzed to determine its chemical and physical properties. It was then thoroughly mixed with Sawdust and Rice husk separately and standard fireclay brick specimens prepared. They were then tested for properties such as refractoriness, fired shrinkage, apparent porosity and thermal shock resistance. Physical property test results showed that refractoriness reduced from 1300 C to 1200C on addition of both Sawdust and Rice husk as additives; shrinkage reduced from 3.89% to 3% on introduction of additives while thermal shock resistance of samples with additives are ten times better; porosity of the sample with Rice husk additive is 36.74%, that of the sample with Sawdust was 45.34% as compared with that of the sample without any additive which was 27.15%. bulk density reduced from 1.98g/cm to 1.59g/cm and 1.52g/cm on addition of Sawdust and Rice husk respectively. Chemical composition tests showed a decrease in silica content from 62% to 54% on addition of additives; alumina content reduced 20% to 12% while iron oxide content increased from 7.58% to 8.38 and 7.99% on the respective addition of Sawdust and Rice husk to the clay material.