EFFECT OF ALUMINA ADDITIONS ON THE REFRACTORINESS AND OTHER PROPERTIES OF SOME LOCAL FIRE-CLAYS FOR USE AS FURNACE LINING

Abstract

This research was carried out on fire clay sample materials collected from two locations (in Ogun State), which were blended with alumina obtained from Aluminium Smelting Company of Nigeria, Ikot Abasi, Akwa-Ibom State to determine their suitability as high refractory for use in furnace lining in foundry Industries. It was revealed that, blending the two fire clay samples (Onibode and Owode-Ketu) with alumina in various proportions such as; 60:40, 70:30, 80:20 and 90:10, respectively gave an improved refractory properties. The result of the analysis shows that these clay deposits can be used as high refractory lining in the foundry Industries. Onibode fire clay produced good refractory materials with the addition of alumina, with improved and acceptable service properties that give better results which can be used for lining of furnaces for melting of metals and its alloys compared to Owode-Ketu fire clay. The refractoriness of Onibode material is above 1600°C, while that of Owode-Ketu is 1580°C with the blended alumina. The crushing strengths of Onibode and Owode-Ketu clays are 16.3 MPa and 22.7MPa, respectively. With the addition of alumina the crushing strengths of the mixtures for the various proportions as shown in Table 3 are: 21.3, 16.3, 18.2, 12.8, 19.2, 25.6, 19.2 and 18.1 MPa, respectively, which are also within the acceptable standard. The result of the analysis shows that these clay samples can be used as refractory lining in the Foundry Industries.