GB812320A - Method and apparatus for producing carbonaceous materials for electrodes - Google Patents

Abstract

812,320. Ball mills; screening apparatus. KENNEDY VAN SAUN MFG. & ENG. CORPORATION. July 2, 1957, No. 20855/57. Classes 59 and 117 A method of producing carbonaceous material for electrodes comprises the steps of subjecting raw unground carbonaceous material to a grinding operation in a single grinding zone to produce finely ground carbonaceous aggregate, air-sweeping the grinding zone with an air stream to selectively remove therefrom the finely ground carbonaceous material, selectively removing the coarsely ground aggregate carbonaceous material from the grinding zone, separating the finely ground carbonaceous material from the air stream, and mixing the coarsely ground aggregate and finely ground carbonaceous materials to produce a mixture suitable for making electrodes. Apparatus for carrying out the method comprises a rotatable cylindrical ball mill drum 12, Fig. 1, to which raw carbonaceous material and air are supplied through an inlet 24, the discharge end of the mill being provided with a shoot 26 through which a stream of air and finely ground carbonaceous material is drawn and with a duct 28 through which the coarsely ground carbonaceous material is discharged. The stream of air and finely ground material is drawn from the shoot 26 by means of a fan 32 and delivered in succession to cyclone separators 35, 37, the fine materials from which are delivered through ducts 39, 40 into a common duct 41 and then into a mixer 42 to which are also delivered the coarse material discharged through the duct 28 by means of a motor-driven screw conveyer 43, and hot pitch or tar from a container 45. The electrode paste formed in the mixer 42 is delivered to electrode moulds by means of a motordriven screw conveyer 47. The coarsely ground material is separated from the finely ground material by means of a screen 50, Fig. 2, having on the outlet side thereof three equally-spaced curved lifters 54 each associated with a web 54 and a pivotally-mounted shoot 68 by means of which the coarsely-ground material is delivered to a cylindrical member 64 provided with helical fins 65 and thence to the duct 28. The member 64 is supported by brackets secured to the helical fins 63 of a member 61, the fins 63 returning to the mill drum any coarse material separated out in the delivery shoot 26. The shoots 68 are simultaneously adjusted and set, according to the amount of coarselyground material required, bymeans of a control 30 comprising a rotatable rod 72 movable longitudinally by means of a pivotally-mounted lever 91 which is locked in the desired position by means of a handle 107. The casing of the shoot 26 has welded thereto the plate 82 of a manhole cover unit, the plate 82 carrying a pair of normally-closed inspection tubes 110 (not shown). The trunnion 16 is provided with a flange 60 to which a ring driving gear is secured.