GB708595A - A method and apparatus for the purification of titanium tetrachloride - Google Patents

Abstract

708,595. Electrolytic purification of titanium tetrachloride. TITAN CO.; Inc. June 11, 1952 [June 12, 1951], No. 14758/52. Class 4<SP>1</SP>. Impure titanium tetrachloride is purified by reduction to a lower chloride in the cathode region of an electrolytic cell and recombination with chlorine to reform the tetrachloride in the anode region. The reactions may take place in a fused bath consisting of a chloride of one or more of the alkali or alkaline earth metals or magnesium, preferably a eutectic mixture. Treatment may be effected in the cell shown, the titanium tetrachloride being introduced through the tubular cathode. 13 into a fused mixture of strontium chloride, sodium chloride, titanium dichloride and titanium trichloride at 700 ‹C. The titanium tetrachoride is reduced at the cathode and migrates to the anode zone where it recombines with chloride produced at the graphite anodes 16 and is withdrawn at 21. The upper portion of the cathode is surrounded by a barrier ring 17 of fused silica surmounted by a cover 18 comprising means 19 for introduction of inert gas such as helium or argon. The cathode may be of nickel or tantalum and may have a silica lining 22. The cell 12 may be of fused impervious silica with an outer sheath 13 of stainless steel. The cell may be heated by gas-burners 11. The current employed is preferably limited to 1.1-1.6 faradays per mol of titanium tetrachloride introduced in order to prevent reduction to metallic titanium.