Abstract: A pneumatic jigging screen device has an air chamber for generating pulsation which is connected to a compressed air source. An air outlet is provided. An air inlet valve in the form of a disk valve is connected between the compressed air source and the air chamber and includes a valve rod. An air outlet valve in the form of a disk valve is connected between the air chamber and the air outlet and includes a valve rod. A first pneumatic valve drive is coupled to the valve rod of the air inlet valve. A second pneumatic valve drive is coupled to the valve rod of the air outlet valve. A first electromagnetic control valve is connected between the first pneumatic valve drive and the compressed air source. A second electromagnetic control valve is connected between the second pneumatic valve drive and the compressed air source.

Abstract: A method and apparatus for treating minerals such as coal in a jig bed having a downwardly opening air chamber beneath the bed wherein the chamber has an air compartment at the upper end retaining a cushioned pillow of air between each jig pulsation with controlled air admitted and relieved from the chamber so that when air is relieved, the water rising in the chamber compresses the air at the upper end and a cushion of air is retained so that with admission of pressurized air, the cushion aids in forcing the column of water from the chamber, particularly at the beginning of operation of the jig.