Fireclay bricks produced from lithomargic clay

Lithomargic clay underlying Awaso bauxite deposits is non-plastic and therefore cannot be used to produce ceramic bodies. The plasticity of lithomargic clay has been enhanced by addition of 20 wt% of clay binder, moulded, dried and fired at 1350 and 1400 oC, respectively. The dwell time was varied from 30 to 120 minutes. Properties such as bulk density, apparent porosity, linear firing shrinkage, and compressive strength were investigated. Crystalline phases after firing were determined using X-ray diffraction technique. The results show the properties measured depends on both the temperature and dwell time. The optimum compressive strength for such bricks could be achieved either by firing at 1350 oC for 120 minutes or at 1400 oC for 30 minutes.