Patent GB-773535-A (GB)
Title: Improvements in or relating to production of chlorides of metals
Inventor: GIBSON ALLAN ROBERT
IPC: C01G1/06
Filed: 1954-03-24
Abstract: Anhydrous chlorides of beryllium, cerium, niobium, thorium, titanium, uranium and zirconium are obtained by subjecting an oxide thereof to the action of gaseous chlorine in a chloride melt in the presence of a sulphide, there being present in the reaction a metal having more than one stable valency.  The chloride melt is preferably an alkali or alkaline earth metal chloride or mixtures thereof and the sulphide, preferably an alkali or alkaline earth metal sulphide, may be present in excess of half of one sulphur atom for each chlorine atom to be combined with the metal, beryllium, cerium, niobium, thorium, titanium, uraniam or zirconium.  The metal having more than one stable valency may be that of which the chloride is desired but in the case of beryllium and thorium, ferrous sulphide or ferric chloride in an amount of 2 to 4 per cent based on the reactants may be added.  The chloride melt is suitably formed in an alumina vessel from which the air is displaced by an inert gas which in turn is replaced by chlorine. An intimate mixture of the oxide to be treated and a sulphide may then be added progressively, preferably in pellets and the flow of chlorine discontinued when sulphur evolution has ceased. The metal may be recovered from the chloride produced by cementation with magnesium or calcium or alternatively the metal chloride produced may be volatilized.  According to an example a mixture of barium and potassium chlorides melting at 669 DEG C. was introduced into an alumina vessel in an electric furnace. Uranium dioxide and barium sulphide were added in pellets and when the chloride mixture had melted a stream of argon followed by a stream of chlorine was passed through the vessel and the pellets of the charge slowly added.  When the evolution of sulphur had ceased the chlorine was stopped and metallic uranium was obtained by sweeping the vessel with argon and adding magnesium metal.  The chloride mixture was dissolved in water leaving small particles of uranium.ALSO:Anhydrous chlorides of beryllium, cerium, niobium, thorium, titanium and uranium, and zirconium, from which the metals may be obtained by reduction with magnesium or calcium are obtained by subjecting an oxide thereof to the action of gaseous chloride in a chloride melt in the presence of a sulphide, there being present in the reaction a metal having more than one stable valency.  The chloride melt is preferably an alkali or alkaline earth metal chloride or mixtures thereof and the sulphide, preferably an alkali or alkaline earth metal sulphide, may be present in excess of half of one sulphur atom for each chlorine atom to be combined with the metal, beryllium, cerium, niobium, thorium, titanium, uranium or zirconium.  The metal having more than one stable valency may be that of which the chloride is desired but in the case of beryllium and thorium, ferrous sulphide or ferric chloride in an amount of 2 to 4 per cent based on the reactants may be added.  The chloride melt is suitably formed in an alumina vessel from which the air is displaced by an inner gas which in turn is replaced by chlorine.  An intimate mixture of the oxide to be treated and a sulphide may then be added progressively preferably in pellets and the flow of chlorine discontinued when sulphur evolution has ceased.  The metal may be recovered from the molten chloride produced by reaction with magnesium or calcium. According to an example a mixture of barium and potassium chlorides melting at 669 DEG C. was introduced into an alumina vessel in an electric furnace. Uranium dioxide and barium sulphide were added in pellets and when the chloride mixture had melted a stream of argon followed by a stream of chlorine was passed through the vessel and the pellets of the charge slowly added.  When the evolution of sulphur had ceased the chlorine was stopped and metallic uranium was obtained by sweeping the vessel with argon and adding magnesium metal.  The chloride mixture was dissolved in water leaving small particles of uranium.