Improved process for the electrolytic decomposition of anhydrous magnesium chloride and the production of magnesium and chlorine

摘要

152,402. Ashcroft, E. A. July 9, 1919. Electrolytic furnaces. - Fused anhydrous magnesium chloride, free or practically so from other substances, is used as electrolyte in both a primary and a secondary cell. A body of lead-magnesium. alloy may form one electrode of each cell. The cells 1, 2, Fig. 1, may be connected in series by conductors x.All their upper parts the cast-iron or other cells may be protected from the electrolyte and chlorine by a lining 13 of fire-clay or magnesite brick. Each cell supports an insulated cover 11 carrying the upper electrodes and provided with charging holes for crystalline magnesium chloride, which may be prepared as described in Specification 152,401, [Class 1 (ii), Inorganic compounds other than &c.]. For a current of 5000 amperes there may be 20 graphite anodes 9, of about 3 in. diameter, immersed 3 in. in the electrolyte and 1 in. from the surface of the alloy. Connexion may be made by conductors 14, dipping into molten lead in holes in the cover and in the anodes. In the secondary cell, the cathodes may be carried by four separate subsidiary covers 15. For each cover there may be 70 iron or steel cathode rods, 10 of # in. diameter immersed ¢ in. in the electrolyte and ¥ in. distant from the alloy. Each subsidiary cover is connected to the main cover by a flexible conductor 16. On opposite sides of each cell are inlet and outlet walls 6, 7, Fig. 3, opening into the body of the cell through passages 4, 5. A weir 8 also interposed between the main bodv of the cell and the outlet well maintains the required level of the alloy. Preferably, electrolysis is carried on for, say, six hours without disturbance of the alloy. The small covers of the secondary cell are then removed successively, and the floating masses of molten magnesium ladled out, without interrupting the current. At intervals, preferably immediately after the removal of the metal, the alloy is transferred from one cell to the other, by ladling, or by communicating passages, or otherwise. A temperature of 750‹ C. is suitable for electrolysis; preferably there is used sufficient current to maintain this temperature. Specification 26813/05 also is referred to.