Abstract: A concentrator comprises a beneficiating member (7) a shaft (9) of which is arranged with an eccentricity relative to the hub (5) of a base (3), and a drive mechanism (2) imparting to the beneficiating member (1) movement about a radius equal to the eccentricity. The housing (14) of the beneficiating member is cylindrical accommodating tapered separating trays (16) arranged one under the other and having by-pass ports (22) of a flow area reducing from the upper to the lower tray.

Abstract: A concentrator comprises a beneficiating member (1) in the form of a bowl with a tapered bottom (2) a concavity of which is provided with a discharge hole (13), and a drive mechanism (5) a hollow drive shaft (8) of which accommodates eccentrically a shaft (10) carrying the beneficiating member (1) executing a circular movement about a radius equal to the eccentricity. In cross section the bowl is elliptical and is connected to a base (3) by flexible elements (12), whereas the concavity of the tapered bottom (2) is offset relative to its shaft (10). A tray (14) for finally concentrating the material is provided under the discharge hole (13).