GB852369A - Improvements in or relating to a process for the electrolytic production of fluorineand apparatus therefor - Google Patents

Abstract

852,369. Electrolytic production of fluorine. IMPERIAL CHEMICAL INDUSTRIES Ltd. Dec. 19, 1958 [Jan. 6, 1958], No. 433/58. Drawings to Specification. Class 41 In a process for producing fluorine by electrolysis at temperatures of 80 to 110‹C. from a fused, substantially dry mixture of KF and HF having an approximate composition of KF 1À8 HF to KF 2À2 HF under non-polarisation conditions with no evolution of fluorine as free bubbles at a vertical, solid, gas-permeable carbon anode of uniform cross section which is surrounded about its upper portion by a spaced gas-impermeable barrier, e.g. of mild steel, nickel or a nickel-copper alloy, which dips below the level of the electrolyte, and is surrounded about its lower portion by a cathode which lies below the barrier, the anode-barrier separation does not exceed # inch at least at the bottom of the barrier, and no part of the barrier approaches nearer than 1/16 inch to the anode, and the anodecathode separation is from # inch to 1 ¢ inch, both distances measured horizontally. The apparatus is similar to that described in Specification 675,209, but the lower edge of the barrier has an inwardly directed flange and insulation, may be provided between the anode and the bottom of the barrier. The permeability, defined as in Specification 675,209, of the anode lies in the range 1 to 30. A preferred separation for the anode and barrier is # inch to 1/16 inch. Examples are given in which anode current densities between 0À1 and 2À0 amps/square inch and voltages between 5À9 and 8À8 are mentioned. The crosssections of the electrodes and barrier may be circular, square, rectangular or hexagonal, and the cathode may be plain or louvred or made of punched sheet or gauze. Specification 668,465 also is referred to.