White paste for stoneware tiles for pavement using raw clay material from Burkina Faso

Abstract

Raw materials from Burkina Faso were used in the production of white pastes for stoneware tiles for pavement. The basic material which is kaolin clay (Loulouka) was added with some natural plastic clay (Korona), feldspar, talc, sand for the formulations of batches for these tiles. Four batches (S1, S2, S3 and S4) consisting of raw basic clay material, plastic clay, feldspar, talc and sand have been prepared for the elaboration of tiles sintered up to 1,150 °C. The changes during the sintering process of tiles were investigated by means of X-ray diffraction and scanning electron microscopy. Mainly mullite, enstastite and glassy phase were formed during the sintering at 1,150 °C. Also the physical properties (water absorption, linear shrinkage) and flexural strength of the tiles were measured. These above properties were improved notably with increasing temperature because of mainly the formation of mullite and glassy phase which reduces the number of pores and their size. The tiles fired at 1,150 °C obtained with batch consisting of 62 % mass of basic material, 20 % mass of feldspar, 10 % mass of sand, 5 % mass of plastic clay and 3 % mass of talc (S4) belong in Europeans Standards-class BIb.