The continuous digester system has an inlet defined therein for the feed of a chips suspension and an outlet for the output of a cooked suspension of pulp. The invention particularly relates to an improved process for the production of ceramic tiles using industrial wastes such as iron ore slime, fly ash and blast furnace slag. A bar extends between a front end and a rear end of the inner rail. The non-hardening pre-compression fluids may be exchanged with grout to fill a void formed by cavity expansion and previously occupied by the non-hardening, pre-compression fluid. Further, interference between the respective sides of the first rectangular parallelepiped and second rectangular parallelepiped is judged through division into the planes X-Y, Y-Z, and Z-X.