Abstract: The invention relates to a dehydrating centrifugal sieve of small overall dimensions, small weight and big yield. The sieve is appropriated for dehydration, de-sludging, enrichment and classification of mineral grains.The sieve according to the invention has in a common housing (1) several conical sieve elements (2), (12), (13) disposed successively under each other and at the same time inside each other. Between particular sieve elements there are funnels (4) terminated at the bottom with a circumferential gutter (5). The circumferential gutter (5) is connected by pipe passages (6) situated in an offtake (7) of granular concentrate through a flow-off surface (9) with an offtake (10) of clarified liquid.

Abstract: Method of separation of a mixture of mineral grains with differentiated sific gravity, under the conditions of a restricted sedimentation, in a cylindrical device, consists therein that the mixture A of the mineral with water is radially supplied to a trough 2 formed around the upper edge of the wall 1 of the water box. The mineral circulating in the trough 2 is desludged and partially separated according to the weight of the grains, and then, under pulsating action of the water, is displaced in a ring-shaped working trough along spiral trajectories towards the conduit 17 and 19 taking out the light fraction D and towards the conduits with a flap 16 for discharge of the heavy fraction C. The pulsating motion of the water is effected by compressed air being cyclically fed to the ring-shaped air chamber 6 via the pulsation valves 14 from a ring-shaped tank 5 arranged around the water box. From the air chamber 6 additional air chambers 7 extend radially beneath the sieve deck 7.