Patent GB-1420279-A (GB)
Title: Separaring granular minerals
IPC: B07B13/00
Filed: 1973-08-21
Abstract: 1420279 Apparatus for concentrating minerals YAKUTSKY NAUCHNO-ISSLEDOVATELSKY I PROEKTNY INSTITUT ALMAZODOBYVAJUSCHEI PROMYSHLENNESTI 21 Aug 1973 39636/73 Heading B2H An apparatus for separating granular minerals into concentrates and tailings, e.g. for separating diamonds from other minerals associated therewith, comprises a housing 1 with a bottom portion adapted during separation to hold water and divided into two compartments 2, 3 for collecting tailings and concentrate respectively; a drum 6 mounted for rotation within the housing so that its peripheral surface passes through the water during separation; a device 10 for applying a coat 11 of a sticky substance to the peripheral surface of the drum; a feeder 12 for supplying a single layer of the granular minerals into the housing: at least one roller 13 held in the housing 'adjacent the feeder, arranged with its axis above the level of the water during separation and having a surface made of a microporous material, the roller being adapted to rotate at a peripheral speed corresponding to that of the drum and being arranged to move radially relative to the rotational axis of the drum to force the granular minerals supplied from the feeder against the surface of the coat of sticky substance on the drum, tailings, during separation, being removed from the drum during passage of its peripheral surface through the water and conveyed to the tailings compartment; a brush 18 for removal of concentrate from the surface of the sticky substance on the drum, the brush being mounted over the concentrate compartment 3, above the water level during separation, and being provided with a rotational drive 19; and a scraper 20 for removing the coat of the sticky substance from the surface of the drum when separation is complete. The drum 6 is driven by a two-speed reversible motor 9. The device 10 and the feeder 12 are pivotably mounted. Each roller 13 is connected through adjustable pull-rods 15 to an eccentric mechanism 16 which effects the radial displacement of the roller. Discs 17 are mounted on the shaft of each roller for frictional driving engagement with end portions of the drum that are free of sticky substance. The water level is controlled by a device 21. In operation, the bottom bath portion of the housing is empty and the drum is first rotated clockwise and the sticky substance is applied to the drum surface by the device 10 which is thereafter pivoted to its inoperative position. The drum is then rotated counterclockwise. The outlets of the compartments 2, 3 are closed by ball valves 5 and the bath portion of the housing is filled with water. Brush 18 is rotated counterclockwise. The discs 17 are brought into frictional engagement with the drum 6 so that the rollers 13 rotate at the same peripheral speed as the drum and contact the surface of the sticky substance 11. The feeder 12 begins to supply a single-layer of minerals to be separated and, at the same time, the ball valve 5 of the compartment 2 is opened. The mineral grains are forced by the rollers against the surface of the sticky substance 11. Upon the sticky substance getting immersed in water, the weakly-stuck mineral grains are torn off from its surface under the effect of water resistance, gravitational and centrifugal forces and are discharged as tailings with water through the outlet of compartment 2. The stuck concentrate grains are continuously removed from the surface of the sticky substance by the brush 18 into the compartment 3 from which they are periodically discharged with water by opening the associated ball valve 5. When the coat of sticky substance is used up, i.e. fully impregnated with concentrate feeding of the minerals is discontinued, the brush 18 is stopped, the rollers 13 are withdrawn away from the drum, the mineral grains and water are discharged from compartments 2, 3, the drum is rotated clockwise and the used-up coat removed by the scraper 20.