Refractoriness Potentials of Ajiwa Clay Deposit Bonded With Rice Husk Ash in Katsina, Nigeria
The potentials for the refractoriness of Ajiwa clay deposit along the lake of the Ajiwa town in Katsina State were determine. The ability of the clay to withstand high temperature without breaking or deforming as well as its maximum allowable temperature were also assessed, the result of chemical and physical properties of the clay shows that, the maximum estimated refractoriness temperature attend are between 12240C to 13490C. The clay sample was obtained and dried in the sun for 10 days. Afterward, the clay sample was crushed, grounded and sieved with a standard mesh of specified measurement (212µ) the rice hush collected was then washed and cleared with spikes, metallic fragments and other foreign elements, then dried in an open air conditions for 5 days. It was burnt in a furnace up to 6500C and allowed to soak for two (2) hours at same temperature after which the rice husk ask was collected and moulded into ratio and dried at room temperature for 24 hours. The chemical analysis was carried out using X-ray spectrometery while physical properties such as porosity, bulk density, linear shrinkage, thermal shock resistance, cold crushing strength and refractoriness were done suing standard techniques. Result obtained shows that the clay composed of silica 64.50% alumina 16.30%, iron oxide 14.20%, calcium oxide 0.2%, potassium oxide 0.74%, titanium oxide 1.71% and other trace oxide in traces. Chemical analysis shows that the clay is mainly of koalinite and free quartz while the physical test shows that the clay has an apparent porosity of 28.46%, bulk density of 1.81g/cm3, linear shrinkage of 6.80%, thermal shock resistance of seven cycles, loss on ignition test of 4.46% cold crushing strength of 14138Nm-2. Considering this results this properties can be improve upon to meet wide range of engineering applications in refractory bricks for furnace lining, tubes for electric furnace, crucible and in rubber and ceramics industries.
Key Words- Refractoriness, Ajiwa Clay, Rice Husk Ash, Oxide, properties