High-pressure particle-bed comminution, using double roll machines (Roller Presses), has of the art for grinding cement clinker, blast furnace slag, cement raw meal, kimberlite and some other bulk solids. There was some reluctancy in introducing the process in ore preparation plants. Newly developed wear protection measures, particularly the ＇＇stud lining＇＇, in connection with some other new design features, now guarantees the necessary availability for hard rock operations. The stud lining is marked by cylinder-shaped metal carbide pieces inserted into the roll surface. In the interstices between the studs an autogenous wear protection layer from compacted feed material builds up. Besides of the wear protection, the compacted layer provides better nipping, consequently thicker flakes and thus a higher capacity of the machine This, inter alia, enables capacities of up to about 1500 t/h for a single Roller Press.