GB728523A - A new or improved method for refining titanium metal - Google Patents

Abstract

728,523. Refining titanium metal. TITAN CO., Inc. Oct. 17, 1952 (Oct. 18, 1951], No. 26153/52. Drawing to Specification. Class 41. A method of refining titanium metal comprises passing current through a cell having a molten electrolyte composed of at least one halide salt of an alkali metal, an alkaline earth metal, or magnesium, or a mixture of such halide salts, and containing lower titanium chlorides in concentration from 0.1 to 5.0 molal, the lower titanium chlorides comprising at least 40 per cent titanium dichloride, the cell having a cathode and employing impure titanium metal as the anode, and maintaining during the passage of the current an anode current density from 0.01 to 3.0 amperes per square centimetre, and a cathode current density of at least 0.1 amperes per square centimetre but not in excess of five times the numerical molality of the lower titanium chlorides present in the electrolyte. It is preferred to have at least 70 per cent of the lower titanium chlorides as titanium dichloride, the remainder being titanium trichloride, and a total concentration of 0.3 to 2.0 molal lower titanium chlorides in the electrolyte. An anode current density of 0.1 to 0.3 amps. per sq. cm. and a cathode current density of 0.2 to 1.5 amps. per sq. cm. is also preferred. The cell may be heated externally by gas flames. The cathode may be made of nickel and the anode may be compacted impure titanium metal. The anode may also be a metallic basket, for example of nickel, containing lumps of impure titanium metal. An atmosphere of argon or other inert gas is preferably maintained above the electrolyte. Specification 632,564, [Group II], is referred to.