Abstract: In a discharge device for heavy matter discharge in settling machines for the processing of coal or other mineral raw materials by means of a bottom drain with variable opening cross-section actuated by a device for sensing the heavy matter layer, at least two bottom drains arranged one behind the other in flow direction are actuated simultaneously by a single sensing device.

Abstract: An arrangement for a rotary cylindrical piston-type slide valve for pneumatic jigging machines includes a housing of symmetrical design including a double rotary piston slide valve portion and a rotary slide valve single portion mounted in a symmetrical arrangement provided for each of the washing compartments.

Abstract: A settling machine for upgrading materials, particularly for upgrading coal, comprises at least one settling chamber filled with water and having a jig screen covering at least a part of the chamber arranged at the water level. The chamber is also connected laterally of the jig screen to a plurality of different pressure sources and the connections are such that pressures may be superimposed on the liquid of the chamber to cause a pulsation thereof for the separation of the material contained on the jig screen. With the method of the invention, the pressure is connected via control lines having control valves which may be adjusted to get a number of settling strokes per minute by pressure surges which may be set to the range of between 20 to 50 settling strokes per minute for one of the control valves, and for the other control valve, may be arranged between 150 and 250 settling strokes per minute.

Abstract: A method and apparatus for the preparation of mineral mixtures, particularly of rough washed coal, on a jig which is controlled by compressed air in which the separating liquid, with the aid of control valves arranged in the supply conduits for air and/or separating liquid, is moved periodically up and down through the openings in the settling material carrier, wherein the pulsating movement of the separating liquid is effected with the aid of an electronic valve impulse control of the compressed air and/or the quantity of separating liquid conveyed to the settling tank.