The disk filters consist of large rotating cloth-covered disks, placed on their side in a tank. The concentrate sludge is sucked through the cloth, and the concentrate is retained by the cloth, while the water is removed along a pipe in the center of the disks. The concentrate sticks to the rotating disk until it is detached by pressure.

The disks of the disk filters consist of 10 sectors. Each sector is covered with a filter cloth. Within the sectors there are channels through which the water leaves during suction. Disk filters were used in the old concentration plant and in the Keretti and Vuonos concentration plants.