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 porcelain tile manufacture. In this case, granules with different characteristics – shapes, sizes, bulk densities, etc. – can be obtained during the granulation operation.
The work reported here evaluated the influence of granular bulk density on the behaviour of porcelain tiles during the different manufacturing stages. Two granulated powders were used, having the same chemical composition and similar shapes and sizes but significantly different bulk densities. An industrial spray-dried composition and a dry route microgranulated powder were employed in this study. The granules prepared from an industrial porcelain tile composition and granulated by different processes presented differences in their bulk densities in the order of 25%. The study began with an evaluation of the size distribution, shape, bulk density and flowability of the granules.