Patent GB-823126-A (GB)
Title: Improvements in electrolytic apparatus
IPC: C25C7/00
Filed: 1957-07-01
Abstract: 823,126. Fused-electrolyte apparatus. HORIZONS TITANIUM CORPORATION. July 1, 1957 [July 25, 1956], No. 20689/57. Class 41. An electrolytic apparatus for producing metals of Groups IV A , V A , and VI A  of the Periodic Table comprises a vessel 10 having means for charging the vessel 10 with a salt, e.g. NaCl, and a salt containing ions of the metal to be produced, and means, e.g. heaters 26, for melting the salt, a vessel 12 for receiving the molten salt and having an anode and at least one cathode 64, Fig. 4, means, e.g. tubes 38, 40, 42, for putting vessels 10, 12 into communication with each other, means for transferring molten salt from vessel 10 to vessel 12 and preventing contamination of the salt during transfer, means adjacent the anode for charging the vessel 12 with material to be refined, means, e.g. a scraper 98, for removing deposited metal from the cathode 64, means, e.g. a withdrawable tray 90, for recovering the metal, and means for maintaining an inert atmosphere in the apparatus. Each vessel 10, 12 comprises a thermally-insulated container 24, 54, respectively, e.g. of graphite, the vessel 12 containing a perforated barrier 66 of an inert material, e.g. graphite, surrounding the cathode 64 which is hollow for circulating cooling fluids and is secured to a hollow withdrawable rod 78 which passes through an aperture in two hinged horizontal baffles 80 in a superposed chamber 76. The container 54 is anodic, and the barrier 66 may be anodic or neutral, the chamber 76 being cathodic and insulated at 72 from the vessel 12 to which it is bolted at 74. Two apertured partitions, e.g. of graphite, separate the barrier 66 from the end walls of the container 54, heaters 56 being suspended in the two end compartments so formed. Operation of the apparatus is as follows:-The apparatus is flushed with a noble gas, e.g. argon, e.g. by connections 36, 75, and the vessel 10 is heated prior to introduction of the salt through a pipe 34. The salt may be electrolysed in the vessel 10 to purify it by substituting a cathode for a hopper 28 above the pipe 34, the container 24 being the anode if made of graphite, or a separate anode being employed if the container 24 is insulating, e.g. being of ceramic. On completion of this electrolysis, the cathode is removed and inert gas delivered by a line 41 to the vessel 10 to force the molten salt through the pipes 38, 40, 42 into the preheated vessel 12, the line 41 being then closed and a vent 140 opened. Material to be refined is introduced by four tubes 120 into the container 54 in the space between the barrier 66 and the partitions and is tamped in place by rods inserted at 128. Charging of the container 54 with molten salt and with material to be refined, e.g. titanium scrap, may take place without interrupting the electrolysis. On completion of electrolysis, the baffles 80 are opened and the cathode 64 withdrawn, metal detached by the scraper 98 falling in the tray 90 which runs on rails 94, the metal being dumped through a valve 105 into a receiver 102 which is flushed with argon after each opening. During scraping, the cathode 64 is accommodated in a water-cooled stack 110. The apparatus may be employed to deposit a metal from a molten salt without a charge of material to be refined being delivered, e.g. as described in Specification 736,567. Specifications 805,767 and 823,125 also are referred to.