Production and characterization of magnesium oxychloride cement bricks for fine polishing of porcelain stoneware tiles

Abstract

Magnesium oxychloride cement (MOC) polishing bricks developed for fine polishing of porcelain stoneware tiles were produced and characterized with respect to MgO/MgCl₂ molar ratio of 6/1, 7/1, and 8/1. X-Ray diffraction analysis revealed that the main crystalline phase formed in the bricks was 5Mg(OH₎₂ .MgCl₂ .8H₂O. Density, abrasion resistance, compressive strength, and chemical durability in water of the MOC bricks were determined to provide information on polishing behavior. Polishing of the tiles was accomplished both in laboratory scale and in online industrial scale. Polishing performance of the bricks was evaluated in terms of average roughness and gloss of the tile surface and of abrasive brick consumption occurred during polishing. The roughness of the tile surface and abrasive brick consumption decreased but the gloss increased when MgO/MgCl₂ ratio in the MOC brick is increased. Scanning electron microscope examinations revealed that the MOC bricks composed of MgO/MgCl₂ ratio of 7/1 had the best qualifications in terms of polishing performance.