COMPARATIVE ANALYSES OF WURNO, DANGE AND WEPPA GYPSUMS IN NIGERIA FOR PLASTER AND CERAMIC PRODUCTION

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Author

Presented To

Department of Environmental Design

ABSTRACT
The raw mineral used world-wide in the production of plaster of Paris is gypsum. This is available in Nigeria. Constant importation of plaster of Paris constitutes a drain on national economy and an added cost on ceramic mass production. Its availability has prompted the central direction of this project to analyse, in a comparative way and to see the possibility of local usage which is likely to cut down cost of ceramic production. Gypsum was obtained from three locations, Wurno and Dange in Sokoto State and Weppa in Edo state. The three samples obtained were labelled and transported from sites to the Ceramic Section, Department of Industrial Design, Ahmadu Bello University, Zaria. They were beneficiated and calcined at the Industrial Development Centre (IDC) at the temperature of 1700C. This was done for the three samples from these locations. Various tests were carried out and they included absorbency, shrinkage, compressive and density tests. These tests aided in determining performance of processed plaster of Paris for ceramic mass production. Results showed that the ratio mix of 75-85 plaster/water ratio mix were suitable for ceramic slip casting process. 65 and 70 plaster/water ratio mix were better used for casting models and press moulding process. The processed plaster of Paris from the three locations; Wurno, Dange and Weppa were used in the production of ceramic moulds which were in turn used for production of ceramic wares. The wares were fired and glazed. This showed that gypsum obtained from the three locations can be used for ceramic application. However, Weppa sample was the best of the three locations in performance and colour followed by Wurno. Dange was good but showed early signs of wearing fatique. Wurno and Dange samples were identified as anhydrites CaSO42H2O while Weppa sample was identified as gypsum CaSO4.2H2O.