Abstract: A centrifuge bowl is used for separating particulate materials of different specific gravity and has a first generally frusto-conical portion of the peripheral wall of the bowl over which the materials are caused to flow, and two axially spaced annular recesses downstream of the first portion and prior to an open mouth of the bowl. The feed materials pass over the peripheral wall causing heavier material to collect within the recesses and the lighter material to discharge through the open mouth. Each recess has a series of angularly spaced discharge ports controlled by pulsed valves. In front of each discharge port is provided a spherical body which directs the material to all sides around the body as it moves towards the discharge port in a generally conical shape. The conical shapes of adjacent discharge ports overlap to provide full discharge of all the material. The first recess acts as a main concentrate collector.

Abstract: A centrifuge bowl includes a flat base and a generally conical peripheral wall upstanding from the base. A jacket surrounding the bowl allows injection of water from a chamber between the bowl and the jacket through openings in the peripheral wall into the bowl for fluidization of materials within the bowl. A feed duct extends to the base and discharges feed materials onto the base for moving outwardly onto the peripheral wall and passing over the peripheral wall. A first portion of the peripheral wall is smooth, imperforate and frusto-conical. At the upper edge of the first portion is provided a pair of axially spaced recesses with injection openings at the base of the recesses for the fluidizing water. Heavier materials collect within the recesses and are discharged outwardly through a plurality of controlled discharged openings around the recesses. Lighter materials escape through the open mouth of the bowl.

Abstract: Method for separating materials of different specific gravities using a centrifugal separator of the type comprising a bowl having a base and a peripheral wall surrounding a vertical axis about which the bowl rotates and a jacket having a base plate under the base of the bowl and a sleeve surrounding the peripheral wall includes a central bottom discharge for the concentrate. The bowl is mounted on the shaft with a hub connecting the shaft to the base plate of the jacket. Water is supplied through the shaft and into the area of the base of the bowl. Tubular discharge ducts extend from holes in the base plate across the space under the bowl to the base of the bowl. These remain open during processing of feed materials supplied to the bowl through a vertical tube feeding onto an imperforate plate carried by the bowl above the tubular ducts, and allow the concentrate washed down from the wall of the bowl to discharge when the feed and the centrifugal action of the bowl are halted.

Abstract: A centrifugal separator of the type comprising a bowl having a base and a peripheral wall surrounding a vertical axis about which the bowl rotates and a jacket having a base plate under the base of the bowl and a sleeve surrounding the peripheral wall includes a central bottom discharge for the concentrate. The bowl is mounted on the shaft with a hub connecting the shaft to the base plate of the jacket. Water is supplied through the shaft and into the area of the base of the bowl. Tubular discharge ducts extend from holes in the base plate across the space under the bowl to the base plate of the jacket. These remain open during processing of feed materials supplied to the bowl through a vertical tube feeding onto a base plate carried by the bowl above the tubular ducts, and allow the concentrate washed down from the wall of the bowl to discharge when the feed and the centrifugal action of the bowl are halted.

Abstract: A method of separately extracting mercury and gold from mine tailings includes a centrifugal separator comprising a centrifuge bowl having a plurality of annular rings on the peripheral surface. An outer bowl or sleeve member provides a jacket from which water is injected through holes in the inner bowl into recesses between the annular rings. Feed materials containing gold and mercury are separated so that the gold and mercury is collected with the heavies in the recesses. The liquid mercury escapes through the holes in the inner bowl onto the inner surface of the outer bowl which is provided with an annular receptacle and is shaped to collect the mercury at the receptacle axially spaced from the open mouth of the bowl. A plurality of outlets in the annular receptacle allow the escape of the mercury into a secondary launder inside the outer launder for the main discharge materials from the open mouth.

Abstract: An enhanced gravity laminar flow separation system is provided by a conical drum which has a plurality of flow channels along the inside surface of the drum. Feed material for separation is fed into the drum and accelerated by an impeller so as to enter the channels at a feed end at the base of the drum and to move along the channels to a discharge end at the mouth of the drum of increased diameter. Heavies are stripped from the base of the channel and the lights escape from the open mouth of the bowl longitudinally of the channel. The channel changes cross-section from the feed end to the discharge end decreasing in width and increasing in depth by the addition of a V-groove at the base. Tangential forces from the acceleration of the material which act on one side of the channel are balanced by the shape of the channel to provide symmetrical flow.

Abstract: A centrifuge bowl of the type having a shell including a peripheral wall and a cast inner liner attached to the inside surface of the peripheral wall is modified by the provision of a plurality of punched channel portions which extend inwardly into the bowl from peripheral wall to define a U-shaped channel with severed ends. During the casting process the casting plastics material extends into the recess behind each channel portion and thus when set forms an insert portion which anchors the liner to the channel portion and thus to the peripheral wall. Openings for the entry of fluidizing water are then drilled through the insert portion from the outside of the shell through one end of the channel portion and through the liner into the interior of the bowl.

Abstract: A centrifugal separator of the type comprising a bowl having a base and a peripheral wall surrounding a vertical axis about which the bowl rotates and a jacket having a base plate under the base of the bowl and a sleeve surrounding the peripheral wall includes a central bottom discharge for the concentrate. The bowl is mounted on the shaft with a hub connecting the shaft to the base plate of the jacket. Water is supplied through the shaft and through a pair of ducts passing through the hub and into the area of the base of the bowl. The discharge also extends through the hub through a pair of ducts which diverge from the central discharge opening outwardly and downwardly into a collection chamber. The discharge duct portions through the hub are angularly offset from the water supply duct portions through the hub so that both can be formed in the hub.

Abstract: A centrifugal separator for gold or the like is of the type in which a bowl is rotated at high speed so that materials fed into the bowl pass over the peripheral wall of the bowl to an open mouth. On the inner surface of the bowl is provided a series of ribs defining peripheral recesses in which the heavy material is collected. An outer shell surrounds the bowl and defines with it a chamber into which water is injected to pass through openings at the base of the recesses to fluidize the material within the recesses. The outer shell has a peripheral wall of increasing diamter toward the open mouth with a plurality of openings being provided in the shell around to open mouth to allow the escape of silt collecting in the chamber. A wear resistant plastics material is attached to the bowl at the open mouth and to a casing surrounding the open mouth to redirect the exiting materials to an outlet duct.

Abstract: A centrifugal separator for use for example with the extraction of gold of the type comprising a bowl with a plurality of rings on the inner peripheral surface between which are provided openings for the injection of water between the rings into the interior of the bowl is modified by a number of further features. Thus firstly the rings and recesses between the rings are molded from a plastics inner which is cast in place within an outer rigid bowl. The openings are formed by punched depressions in the outer wall formed prior to the casting and then drilled subsequent to the casting to form a tangential opening. The shape of the recesses defines sides tapered outwardly toward a flat base at a shallow angle of the order of 15 degrees with the width of the base wider than the width of the injection openings.

Abstract: A centrifugal separator of the type comprising a bowl which is rotated about its axis and which has on the inner surface of the peripheral wall, a plurality of axially spaced radially extending rings and in between the rings, a plurality of openings through which water is injected from outside the bowl, has the openings arranged tangentially to the surface of the bowl and in a direction opposite to the direction of rotation to improve the fluidization of the material on the peripheral surface of the bowl. The openings are manufactured from a plurality of separate wall portions, each of which has projections stamped outwardly which are then drilled to provide tangentially extending holes. The wall portion is then rolled and assembled with a plurality of rings into a bowl where each wall portion is of greater diameter than the previous bowl portion closer to the base. An opening in the base lies under the lowermost ring and extends into a projection from the lowermost peripheral wall portion.