GB857602A - Improvements in or relating to high temperature electrolytic cells - Google Patents

Abstract

857,602. Fused-electrolyte cells. COMMISSARIAT A L'ENERGIE ATOMIQUE. June 4, 1957 [June 7, 1956], No. 17749/57. Class 41 An electrolytic cell 1 for producing high purity metals and alloys by electrolysing a molten salt comprises a muffle 5 having at least the inner walls of metal, a crucible 11 of an electrically conductive refractory material, e.g. graphite, removably disposed in the muffle 5 and forming one electrode, a further electrode 25, and means 14, 12 electrically insulated from the muffle 5 for leading current to the crucible 11. The cell 1 communicates through slide valves 3, 4 with a cooling chamber 2. The crucible 11 is connected as anode through a conducting plate 12 and a wire 14, the plate 12 resting on insulation 13 in the muffle 5 which is heated by an electric heating element 7. A cathode 25 depends from packing 26 in the chamber 2 which has a cooling water jacket 23. Each valve 3, 4 comprises two members 34, 35 forming a casing in which is slidable a rod 36 carrying a plate 37 and a cover 38 which may be raised or lowered by rotating the rod 36 to actuate a cam 40 on the rod 36. There are joint packings between the members 34, 35, 38, e.g. at 33, 39. The cell is operated as follows:-With the chamber 2 removed, air is withdrawn from the muffle 5 by a pump attached to a valve 21, the muffle being heated. Next, inert gas is admitted at 17 into the muffle to restore the pressure, and the electrolyte salts put in the crucible 11. The salts, if desired after being degassed, are heated in an inert atmosphere or in a vacuum, and when molten, inert gas is introduced at 17, and leaves at 21. The chamber 2 is then fitted to the cell by screwing the valve 3 to the valve 4, degassed if desired, and the valves 3, 4 opened, the inert gas leaving at 24, and the cathode 25 lowered. When electrolysis is completed, the cathode 25 is raised, the valve 3 closed, and the cathode left to cool in the chamber 2. In a modification, electrical contact to the plate 12 is by a rod in the conduit beneath the plate 12 which leads to the exterior of the cell. Specification 851,444 is referred to.