Abstract: The invention provides an extraction device (1) for liquid suspensions and pulps and is designed for use in the field of mineral processing. The extraction device includes two adjacent upstream and downstream concentric chambers (2) and (3) defining a feedwell (4). The feedwell is centrally located upstream of a third chamber in the form of a thickening tank (5). All three chambers are in sequential unidirectional fluid flow relationship such that feed liquid flows firstly from chamber (2) to chamber (3) and then to the tank (5).

Abstract: The invention provides a dilution apparatus for a thickener of the type having a thickening tank and a feedwell disposed upstream of the tank to receive feed liquid, said dilution apparatus including: a receiving vessel adapted for at least partial submersion within the thickening tank to receive supernatant dilution liquid therefrom; and a submersible pump including an impeller adapted for at least partial submersion within the dilution liquid, the pump being adapted to transfer the dilution liquid from the thickening tank through the receiving vessel to the feed liquid for dilution thereof, before transfer of the feed liquid from the feedwell into the thickening tank. The pump is responsive to system parameters for adjusting the flow rate of the supernatant liquid.

Abstract: The invention provides a flotation device including a thickening tank (1) having right cylindrical sidewalls and a downwardly sloping frusto-conical floor. A drive shaft (2) is centrally rotatably mounted within the tank. Each one of a plurality of rake arms (3) is fixedly connected to the drive shaft and extends radially outwardly, substantially parallel to the tank floor. Each arm supports an array of blades (4) extending axially into the tank. An array of baffles in the form of rectilinear baffle plates (5), fixed relative to the tank, extends axially into the tank in complementary alternate radially spaced relationship with the blades (4). The baffle plates are located within the swept volume of the blades to retard fluid rotation in response to the rotation of the rake. A diametrical service bridge (6) is fixedly connected to the tank for mounting the baffle plates.

Abstract: A pinch valve (10) comprising a flexible sleeve (12) adapted for attachment to a conduit in communication with a source of fluid, pinching means (26) adapted to pinch the flexible sleeve (12) and thereby reduce the effective cross-sectional flow area thereof, actuation means (28) operable selectively on said pinching means (26) to regulate fluid flow through the sleeve (12) and mounting means (42) disposed to support the actuation means (28) independently of the sleeve (12) and thereby to permit removal of the sleeve (12) without removal of the actuation means (26).