Comparison between spray-dried and dry granulated powders in the fabrication of porcelain Tiles

摘要

Porcelain tiles have traditionally been manufactured by pressing granules prepared in spray driers. However, in recent years, several studies have investigated the possibility of using the dry route process as a new alternative for the fabrication of porcelain tiles. In this case, granules with different characteristics - shapes, sizes, bulk densities, etc. - can be obtained during the granulation operation. To perform this study, two granulated powders were prepared by spray drying and dry granulation, having the same chemical composition and similar sizes. The study began with an evaluation of the size distribution, shape, bulk density and flowability of the granules. Prismatic samples were then prepared and the behavior of the powders produced by different granulation processes in response to pressing, drying, and firing was examined. The results indicate that the granules with higher bulk density prepared by the dry route were less deformable during pressing. As a result, the microstructures of the green and fired bodies obtained were significantly different.