Abstract
The influence of the correlation between the drying constant and the diffusion coefficient of the liquid on the behavior of two raw materials for brick manufacturing during their drying process was examined. The test was performed in a laboratory dryer with air recirculation. It has been observed that the behavior of some raw materials during fast drying process regimes does not depend only on external drying conditions, but also depend on internal controlling mechanisms, in this case moisture diffusion in the slab.