Improved furnace for the production of aluminium by electrolysis of the molten salt, operating at constant level of liquid

摘要

881,453. Fused-electrolyte apparatus. MONTECATINI SOC. GENERALE PER L'lNDUSTRIA MINERARIA E CHIMICA, and DE VARDA G. Jan. 27, 1958 [Jan. 31, 1957], No. 2614/58. Class 41. A furnace for the continuous production of aluminium by electrolysis employing consumable anodes 104 has a passageway 103 extending upwardly from a collecting chamber at the bottom of the furnace for aluminium 106, the lower end of the passageway 103 being in communication with the aluminium 106, e.g. through a hole 108, and having near its upper end an outlet 110 through which aluminium is automatically and continuously discharged into a receptacle 112 which is separate from the collecting chamber. Aluminium 111 in the receptacle 112 can thus be removed at any time without disturbing the electrolysis process. The passageway 103 is formed between two refractory walls 107, 109. Alumina is fed continuously to the bath 114 to keep the level constant, and the spacing 105 between the anodes 104 and the molten metal 106 is kept constant by adjusting the position of the anodes. It is stated that this may be done automatically. The invention is applicable to multi-cell furnaces, e.g. of the necklace type described in Specification 814,754 in which the bath is circulated by passages 10, Fig. 4, through all the cells which employ bipolar electrodes 4. Aluminium 11 collects in a lower chamber 21 formed at the bottom of each cell between refractory supports for the electrodes 4. Each chamber 21 communicates through a hole 12 in a wall 13 with a pocket 28 leading to a receptacle 29 through outlets 24. The recaptacle 29 may have lateral and/or longitudinal walls 30 to separate the outputs of different groups of cells. Each cell has three anode faces 4 at one side and three corresponding cathode faces at the other, each group of three bipolar electrodes being separated by walls 13 in which the passages 10 are formed. The walls 13 and outer walls 23 have grooves to locate ribs in the electrodes. Specifications 800,092, 846,305, 846,331 and 847,970 also are referred to.