Abstract: A roller press, for the thermal compaction and briquetting of loose material, having rollers each comprising a core having a cylindrical outer surface and a shell carried on the core, the shell being formed from a plurality of adjacent segments each extending longitudinally of the roller and having longitudinal edges parallel to the axis of the roller and detachably secured at their ends to the roller core, circumferentially-spaced cooling ducts parallel to the axis of rotation of the roller being provided in the roller core at positions inwardly of the outer surface of the core and interconnected to form at least one cooling circuit provided with an inlet and an outlet for the passage therethrough of a coolant. The cooling ducts in the roller core can be connected in series or in parallel.