Abstract: An autogenous grinding mill (10) includes a support casting (12) and a drive motor (14) which rotates a drum (18) defining a generally cylindrical grinding chamber. The other end of the chamber has a discharge opening (22) through which a stationary shaft (24) passes. One or more shear-inducing members (26, 26′) are affixed to the shaft (24). A continuous feed of flowable particulate material, for example a slurry or power, is introduced to the rotating grinding chamber via feed passage (28) passing trough the stationary shaft (24). The mill also includes means for introducing a fluid into a layer of material being ground to contact that material. This means can be the same passage (28) used for the feed material or might be a separate passage.

Abstract: A grinding mill has a rotating container (40) into which particulate material is fed. The container is rotated above critical speed to form a layer which is retained under high pressure against the container inner surface. Shearing discs (58) mounted inside the container induce shearing of the layer to promote particle fracture by shearing and abrasion in the pressurised layer. Fine ground material travels axially to the container discharge end (64). In one form of the invention, the container is rotated at sufficient speed to form a series of solidified zones (70) alternated with stirred zones (72) next to non-rotating shearing discs (58). These solidified zones act as solid discs rotating with the container.

Abstract: A centrifugal jig has a container mounted for rotation about its longitudinal axis. The container is separated into an axial region and a peripheral region by ragging material supported by a screen. The peripheral region is composed of a series of hutch chambers with reciprocating wall portions located radially outside the screen, for repetitively dilating the ragging. The disclosed hutch chamber construction has a reciprocating wall portion which includes convergent wall surfaces that narrow toward the hutch chamber concentrate outlet.

Abstract: A centrifugal jig of the type in which a feed slurry is introduced into a rotating chamber bounded radially by a screen provided with ragging on its inner surface. The ragging is repetitively dilated in a circumferential sequence while the container rotates.

Abstract: A centrifugal jig of the type in which a feed slurry is introduced into a container rotating about a vertical axis in a region radially bounded by a screen. The screen is preferably substantially parabolic in shape. Ragging is provided on the screen's inner surface and water is provided in the hutch region on the opposite side of the screen. The water in the hutch region is pulsed repetitiously to dilate the ragging and pulsion of the hutch water is achieved at an interface such as a diaphragm interface or an air/water interface. The interface is positioned substantially wholly beyond the projected free surface of the feed material.