ABSTRACT

This study involves development of models for composing Ohiya clay-feldspar-silica mix into varying qualities of ceramics products in accordance with end users desires in other to attract investors in industrial scale by harnessing of this neglected natural resources in Abia State for the economic gro\\ thof Nigeria. The ceramic products considered include refractory bricks, tiles, electrical insulators. tablewares and water candle filter. The mineralogical and chemical content of this clay deposit were analysed using X- ray diffractornetry and X- ray fluorescence spectroscopy. The properties of the ceramics produced from varying matrix of this clay and its additives were investigated and quantified using two levels, central composite response surthce design and models. The apparent porosity, linear shrinkage, apparent densit\ . water absorption rate. cold compressive strength. modulus of rupture and refractoriness constituted the ceramic properties or responses studied. Optimal products design for producing standard refractory bricks, tiles, tableware, low/high voltage insulators and ceramic water candle filter from this clay were determined using desirability function analysis. The cost and savings involved in the application of the developed Ohiya clay based optimal ceramic product formulations were evaluated using the prevailing average market prices in Umuahia. Nigeria beteen June and December. 201 8 Results sho ed that the alum mosilicate content of the clay represented about 91% of the total mineralogical composition of the clay. Response surface study revealed that the main effects of the clayey body mixture factors influence its seven responses significantly with contribution of the quadratic effoct and factor interactions. [he results also revealed that 40:32:21. 42:33:17, 41:32:27 and 42:32:20 are the optimal mix of clay, feldspar and silica for producing refractory bricks, tiles. tableare. and lo/high voltage insulators respectivel\ . vhi Ic the respecti\ e optimal flring temperatures of the cerain ic products were 1200. 1300. 1000. and 1200/1300°C'. In addition, the tile was found suitable for wall and floor applications while the performance test of the ceramic water candle filter indicated a filtration efficiency of 78 and 79% for the fotal dissolved and total suspended solid respectively. Also, the polarization index, insulation resistance at 5000 volts, dielectric strength of the low and high voltage electric insulators were respectively 1 .46. 6.96GQ. 1 7kV/mm and 26kV/mm while the refractory brick had a refractoriness temperature ot 1500°C. The production of refractory bricks, electrical insulator, tiles, tableware and water candle filter at optimal settings saved sixty three naira (N63). three hundred and seventy five naira (M375), twenty eight naira (N28), seventy three naira (N73) and two hundred and forty four naira (N244) respectively, which translated to I 6%. 60%. 9%. 21% and 69% in profit for these products. Ohiya clay was found to have the requisite intrinsic properties for relractor bricks. all and floor tiles. ceramic \ater candle filter. table are and electrical insulator production. I leiice. adopti m of' the optimal mixing ratio and application of the deeloped empirical models as well as exploitation of' this natural resource are recommended.