GB543294A - Electrolytic production of nickel - Google Patents

Abstract

543,294. Electro-deposition of nickel. FALCONBRIDGE NICKEL MINES, Ltd. June 6, 1940, No. 9934. Convention date, July 12, 1939. [Class 41] Malleable and annealable nickel is electrolytically deposited directly from an acidified nickel salt electrolyte, containing traces only of impurities, while a great number of minute air-bubbles are released at the bottom of and within a canvas bag 13 in which the cathode 12 is suspended, sufficient air being released to stir vigorously the electrolyte within the bag so as to prevent the accumulation of hydrogen bubbles, or of solid impurities on the cathode and to prevent the electrolyte next to the cathode from becoming unduly basic, thereby preventing the formation of objectionable " berries" on, or pitting of the nickel. The electrolytic cell may comprise a rectangular concrete tank 10 lined with mastic coating and containing a series of anodes 11, and cathodes 12 within double-walled cathode bags 13 containing also air discharging pipes 14 preferably of porous ceramic material. The edges of the cathodes may be received in grooves in a wooden frame to avoid deposition of nickel at the edges and thus facilitate stripping nickel from the cathode starting sheets. A continuous stream of electrolyte, e.g. nickel sulphate acidified with sulphuric acid to a pH value below 4 and at a temperature 40 to 80‹ C. is passed into the cathode bags, anolyte overflowing at 26 whence it is purified and strengthened for recirculation. The current density may be 0.5 to 5 amperes per sq. dem of cathode surface.