Heat retention body for kiln construction: a blend of Kenyase Abrem and Tepa clays
Attaining high temperature in locally manufactured kilns for bisque and gloss firing in Ghana has been a major challenge for most potters. Due to this challenge, most refractory materials are imported to build kilns for firing ceramics wares to meet modern demands; in most cases potters import electric kilns to fire their products. The cost of acquiring these kilns and refractory materials are very expensive and leads to high cost of production. Over the years, clay workers in Ghana have tried to compose several bodies made of our local raw materials that could serve this purpose but unfortunately these bodies when used for kiln construction are not able to retain much heat to adequate to fire stoneware, porcelain and high temperature glazes. The researcher adopted the descriptive and experiment research method of the qualitative research design to examine, test and produce low-density refractory brick suitable for the construction of high temperature kilns. It was discovered that, Kenyase Abrem and Tepa clays when composed together into a body produces a refractory material that can fire to a temperature between 1300°C (2372°F) and 1600°C (2912°F). It is therefore recommended that, Kenyase Abrem clay being higher in plasticity than Tepa clay, is appropriate for binding the composed body together for producing low-density refractory bricks for kiln construction. Again, the brick made from the composed body when subjected to open porosity test indicating more air pockets in their internal structure that is suitable for retaining heat in kilns to complete a firing process.
A Project Report submitted to the School of Graduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi In partial fulfillment of the requirements for the degree of Master of Philosophy in Integrated Art (Clay and Earthenware Technology), 2015