COMPARATIVE STUDY OF SOME REFRACTORY PROPERTIES OF SELECTED CLAY DEPOSITS IN BIU AND HAWUL LOCAL GOVERNMENT AREAS OF BORNO STATE
Publication Date : 01/08/2008
The paper shows a comparative analysis of some refractory properties of clay deposits in six selected locations of Biu and Hawul LGAs in Borno State for use as fweelays. The clay samples were collected from Gur, Gula and Mangada in Biu LGA and Herne, Kwayabura and Yamarkumi in Hawn! WA. Test specimens were prepared from the samples by standard method (Chester. 1973; Chesti; 1968 and Misra, 1975). The clay samples were tested for five refractory properties, which are the chemical composition, thermal shock resistance, refractoriness, sintering temperature and loss on ignition. The chemical composition was determined using the atomic absorption electro-photometry, sintering point using the heating and inspection methods, alternate heating and cooling method was used to determine the thermal shock resistance. Refractoriness was determined using the pyrometric cone equivalence method. The result of the chemical analysis shows that the alumina (Al20,) content for the entire clay samples is as follows: 21.25% for Gur, 19.68% for Yamarkumi, 18.68% for Herne, 25.88% for Gula, 26.57% for Kwayabura, and 20.00% for Mangada. The alumina content of fireclay generally ranges from 25 to 45% (Misra, 1975). The silica content of Gur (59.20%), Mangada (62%),Gula (57.90%) Yamarkumi (41.80%), Kwayabura (38.30%) and Hema (41.50%). The highest temperatures obtained were for Gula and Kwayabura 1400°C and the lowest were those for Hema and ivlangada 1300°C but fireclay refractories should have refractoriness in the range of 1500 — 1700°C (Chester, 1973; Chesil; 1968 and Misra, 1975) which implies that the usage of the clay deposits in the two LGAs is restricted to non-ferrous materials processing.
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