METHOD OF EXTENDING THE USEFUL LIFE OF ELECTRODES USED FOR PRODUCTION OF ALUMINIUM IN AN ELECTROLYZER

摘要

Al is produced in an electrolytic cell contg. Al halide (esp. chloride) in a molten solvent bath by (a) moving the bath through the spaces between opposed anode and graphite cathode surface at =1.5 ft./sec. to deposit molten Al on the cathode surfaces, the latter being made of graphite which is wetted by Al; and (b) moving the bath through inter electrode spaces provided with non-wettable graphite cathode surfaces at 1.5 ft./sec. Alternatively, inter electrode spaces provided with wettable graphite cathode surfaces are 0.5 in. wide (0.5-1.5 ins.) and the bath is moved through at relatively low velocity; and spaces with non-wettable graphite are =0.5 wide and the bath is moved through at a relatively high velocity. The wetting or non-wetting behaviour of the graphite can be used in association with bath flow velocity and anode cathode distance to minimise cathode surfaces.