Abstract: A wet jigging mechanism for handling coal or other minerals including a mineral containing tank, a pulsed air chamber opening downwardly into the tank, a compressed air source with a conduit and a vent conduit with valves in the conduit, the valves including pivotal butterfly valves on a shaft with a swing flap operator operated by the compressed air to move the butterfly valve and the swing wing engaging a variable positioned rubber stop damper at the open position of the butterfly valve, and a rubber seat for the butterfly valve in closed position acting as a damper.

Abstract: A method and mechanism for dewatering fine coal or the like by a filtering operation including a horizontally disposed cylindrical housing defining a pressure chamber within, an intermittently movable filter belt wrapping support rolls for the belt at each end with the rolls having driving and braking devices, movable sealing devices positioned at openings to the chamber to seal the belt where it extends into and out of the chamber, a support for the belt with means for draining filtrate dewatered from the coal, and means to apply pressure to the chamber above the belt for dewatering the coal and for providing pressure beneath the support for the belt to balance forces within the housing.

Abstract: A control apparatus for a rotary valve-driven jigging machine for processing coal or other minerals, particularly for a rotary valve-driven throughput jigging machine whose pulse chambers periodically are charged with compressed air in order to generate a pulse motion and are disposed under the jig screen, is characterized in that the level of the working air pressure in the pulse chambers is changed as a function of changes of the size of the stroke of the separating liquid. The change of the level of the working air pressure in the pulse chambers occurs by a controlled throttling of the outgoing air and/or of the incoming air.