GB899509A - Improvements relating to electrolytic furnaces - Google Patents

Abstract

899,509. Agitating furnace charges; charging electrolytic furnaces. ALUMINIUM-INDUSTRIE A.G. Dec. 22, 1960 [Dec. 29, 1959; Oct. 28, 1960], No. 44093/60. Class 51 (2). [Also in Group XXXVI] In an electrolytic furnace for producing aluminium from alumina using a fused fluoride bath, a crust-breaker consisting of two beams 24, 25 carrying crushing teeth 26 is disposed over the full length of a gap 23 between anode sections 19, the beams being adapted to move vertically either alternately or together. Before the crust-breakers are operated, alumina is distributed over the crust 7 from a hopper 27 having a double bottom, the upper part 32 of which is a porous plate supplied with compressed air through ports 34 in pipes 33 to fluidize the alumina causing it to flow freely through perforated walls 35 and out through passages 36. A modification, Fig. 1 (not shown), has a hopper with a bottom row of valve-controlled outlets, and, in another modification, Fig. 4, the beams 25 have pivots 37 at alternate ends of the furnace and are rocked by fluid-operated rams 38, latches 41 being provided to hold the beams in the raised position when out of use. The beams have teeth 26 only on the half of their length remote from the pivots 37. A final modification, Fig. 5 (not shown), has longitudinal beams with teeth along the full length operated by rams at both ends. The bath lining comprises powdered silicon carbide, 70-80% by weight; powdered coke, 15-10% by weight; medium hard pitch, 15-10% by weight; mixed at a temperature of 50-250‹ C. The particle size of the silicon carbide is up to about 6 mm. and of the coke up to about 22 mm. German Specification 895,379 is referred to.