Reusing porcelain tile polishing wastes in the manufacturing of aluminosilicate fireplace bricks

Waste porcelain tile polishing sludges result from sediments of the treatment plants of tile manufacturing industrial wastewater. These polishing by-products are essentially a mix of fine residues of the specific ceramic body and a coarse residue of the abrasive used for polishing the surface of the tiles. In the present work, it was studied the use of porcelain tile polishing sludges, as a raw material in manufacturing of aluminosilicate fireclay bricks to be used in fireplaces. In order to establish the feasibility of the process and to develop the addition conditions, a set of appropriate ceramic compositions of white and red fireclays was studied. Results showed that up to 10% in weight of the basic raw materials could be preplaced by tile polishing dry sludges, without significant changes in the ceramic process and the resulting materials properties.