Preparing porcelain bricks using coal gangue from Fengfeng coal mines

The chemistry and mineralogy of coal gangues from Fengfeng coal mining area in Handan city, Hebei province, and their qualities and grades were evaluated. Porcelain bricks were prepared using different proportions of the coal gangues. Sixteen groups of material prescription were tested. Comprehensive measurement and analysis were made on water, absorption, rate, mechanical strength and shrinkage rate of the brick samples, and their microstructures were observed under SEM. Besides, the reason of occurrence of gas bubbles and pinholes, as well as their impacts on upper limit of sintering range and mechanical strength of brick bodies, were studied. Those comprehensive results of quality parameters show that the coal gangue of sandy mudstone with hypo-high content of iron can be used as raw material producing porcelain bricks with red-brown color, and water absorption rate of brick bodies is lower than 0.5% and rupture modulus bigger than 35 MPa. Especially the content of coal gangue in the prescription can reach up to 80%.