DEVELOPMENT OF CERAMICS WHITE WARE WITH ENHANCED COLOUR ILLUSORINESS USING RAW MATERIALS FROMSOUTH- SOUTH NIGERIA

Abstract

Development of Ceramic White Ware with Enhanced Colour Illusoriness using Raw Materials from South- South, Nigeria White ware is a broad class of ceramic products that are white to off-white in appearance, frequently containing a significant vitreous or glassy component. It is experiential that Nigeria spends well over ninety billion naira annually on importation of various ceramic products of which white ware products account for forty percent of the amount spent. It is observed that local ceramic manufacturing outfits do not place much emphasis on the production of white ware ceramic products but concentrates on the production of earthenware, sanitary and stone ware products. This could be due to lack of competence in the processing of ceramic materials which is heavily contaminated with organic and inorganic impurities. This study is therefore focused on the production of porcelain using cow bone powder, kaolin, ball clay, bentonite, feldspar, flint and calcium carbonate from South-South Nigeria at developing table ware which is expected to exhibit an effective colour decoration that would help local pottery compete favourably in quality and cost with the imported white ware products. The objectives of the study is to identify the materials for the production of white ware ceramic products within South-South, Nigeria; characterize the mineralogical properties of the raw materials for the formulation of white ware body and glaze; formulate white ware bodies and glaze that will mature at 1200oC; produce white products using different ratios and forming methods; evaluate the properties of the locally made white ware ceramics with the imported white ware ceramics; and compare the cost effectiveness of locally produced porcelain to the imported ones in Nigeria, whether found in market or homes. The required raw materials used for the study were bone ash, feldspar, flint, calcium oxide, kaolin; ball clay and bentonite were sourced from their primary location and were crushed, milled and screened into fine powder. The processed powder materials were used to conduct a 36 quadrilateral blends for suitable compositions for white ware body and glaze. The formulated clay body was used to produce table ware using throwing, casting, and jiggering/jolleying methods. The produced wares were allowed to dry and fired to test for porcelain characteristics of the body. The formulated base glaze from the quadrilateral blend model was used for conducting various colour tests using biaxial blend method. The wares were glazed and fired using author’s fabricated kerosene kiln. For the purpose of testing the set objectives, broad field trips were made to various stores in New Benin market, Mission Road (in Benin City) and Onitsha where white ware products are sold. Six imported ceramic white ware products were purchased and numbered 1-6 as samples and tested along side with the author’s experimental product which was numbered 7 for various shear strength tests. This was to determine few tests such as: 1. Moisture content (%), 2. specific gravity (SG), 3. bulk density (g/cm3), 4. dry density (g/cm3), 5. Void ratio (e), 6. porosity (n). All experiments were carried out according to British standard code of practice BS 1377: 1975/2000. Based on the field assessment of the ceramic materials from South South Nigeria as well as experimental tests carried out on materials, the following findings were made: Samples 1 prestige is high in terms of it strength 15.20N followed by the sample 7, authors field work 10.10N, the bulk densities for sample 1 prestige 1.58g/cm3, and author’s field work 1.57 g/cm3 which is an indication that the particles or grains are neatly compacted to form a strong mass object which reflected on high value that was recorded for the shear strength. The porosity for prestige (n) = 0.38, authors field work (n) = 0.39. This is a reflection of the small quantity of moisture content retained in each of the products, thereby producing high resistance to breakages and the gradual defacing or fading of the finished surfaces. The research indicated that high quality white ware ceramic products with enhanced colour illusoriness can be produced in Nigeria using indigenous materials.