METHOD FOR SEPARATION OF QUINOLINE-INSOLUBLE SUBSTANCES FROM COAL TAR AND PITCH Russian patent published in 1995 - IPC

FIELD: coke chemistry. SUBSTANCE: method involves mixing coal tar and pitch with a thinner and filtering them in a centrifugal field or under pressure. The mesh size of the screens is 2-3 times larger than the diameter of the separated quinoline-insoluble substances. The mixture is filtered through a layer of auxiliary filtering substance - crystals of water-soluble salts. The latter are constituted by ammonium rhodanide, ammonium chloride, ammonium sulfate, ammonium phosphate or mixtures thereof. The sediment and auxiliary filtering substance are washed off the filtering surface with a hot solution of water-soluble salts. If filtering centrifuges are used, the salts are washed off after cutting off the sediment together with a part of the layer of crystals of water-soluble salts while the remainder of the layer is washed out of the rotor with a hot solution of these salts. EFFECT: higher efficiency. 3 cl