Physicochemical and Mechanical ...

Ceramic building materials were obtained by mixing silica, feldspars, and kaolinitic and illitic clay of Missole 2 area, meaning 20% of silica, 15% of Na-feldspar and 15% of mixed-feldspar. Samples were shaped from uniaxial pressing of wet granules and then fired up to 1150 °C. They were characterised by porosity, bulk density, microstructure and flexural strength. Structures of fired products containing mullite, hematite and quartz crystals embedded into a porous and interconnected microcrystalline matrix of both clayey and mixed materials. However, dense particles were developed within the matrix of the mixture and decreased the quantity and diameter of pores. Average values of clay ceramics were 2-8 MPa and were lower than flexural strength values of the mixture (15-20 MPa).