GB865919A - Improvements in and relating to electrolytic cells - Google Patents

Abstract

865,919. Fused - electrolyte apparatus. UNION CARBIDE CORPORATION. Dec. 20, 1957 [Dec. 28, 1956 (2)], No. 39752/57. Class 41. An electrolytic cell for separating metals of Groups IV, V and VI of the Periodic Table comprises a crucible 2 for the electrolyte serving as the anode of the cell and positioned in a vacuum chamber 1 having an opening adapted to be closed by a slidable cover 9, a plurality of cathode chambers 8a, 8b, being mounted on the cover 9. Each chamber 8a, 8b has a vertically adjustable, centrally disposed cathode 12a, 12b which may have a protective carbon or graphite sleeve 54 at its lower end adjacent the tip of the cathode, Fig. 5. The cell is operated as follows : A salt mixture, e.g. NaCI-NaF, is fed to the cell and one of the chambers 8a, 8b aligned with the crucible 2, O-rings 10, 11 excluding the atmosphere from the cell. The cell is then evacuated through an outlet, not shown, to about 100 microns of Hg, and an inert gas, e.g. argon, may be introduced. The cell is then heated by means 4, and a halide of the metal to be produced fed to the cell. The cathode is lowered into the fused electrolyte, chlorine being removed continuously. The process is continuous, a cathode being raised when fully charged and allowed to .cool in its chamber, and the cover 9 being moved on wheels 17 along a platform 6 in which is the opening of the chamber 1 to bring the other chamber 8a, 8b into alignment with the crucible 2, the rings 10, 11 preventing ingress of the atmosphere to the cell during this movement. Depression of a clamp 15 lowers a shaft 16 carrying the wheels 17 to bring the wheels 17 into contact with the platform 6 and by reaction slightly raise the cover 9 to facilitate movement thereof along the platform 6. Instead of rings 10, 11, a plastic sheet, e.g. of polyethylene, may be placed between the parts 6, 9 to serve as a seal. Water jackets are provided for the chamber 1, platform 6 and chambers 8a, 8b. In a modification, Fig. 5, the anode comprises a graphite crucible 23 and two parallel, upright perforated graphite baffles, one being 24, 28, which separate heating elements, one being 30, from the central space of the crucible. The crucible rests on porous carbon blocks 25, has a graphite lid 29, and is packed in a granular refractory material 31, e.g. powdered carbon.