Production of uranium

摘要

Pure uranium, or an alloy thereof, is produced electrolytically using as electrolyte an alkaline earth metal halide, e.g. MgCl2 or CaCl2 in which UO2 is suspended, and maintaining the temperature below the melting point of uranium metal, e.g. 850-950 DEG C. The cathode may be inert, e.g. molybdenum, or may form an alloy with uranium, e.g. using a molten layer of aluminium. For example, an aluminium alloy containing 74.2% U is formed corresponding to UAl3. This powder is washed and heated in an alumina boat at 1500 DEG C. in vacuo, yielding a product of 79% U corresponding to UAl2, melting at 1590 DEG C. An iron alloy is made using as cathode a eutectic mixture of U and Fe containing 183 g. U and 26 g. Fe; after electrolysis the cathode alloy contained 89% U compared with 87.6% of the original cathode alloy. In a suitable apparatus, an alumina crucible 1 heated in a furnace 2 is provided with a lid of pyrophyllite having an aperture 5 for the supply of an inert gas, e.g. argon. Carbon black anodes 12a are carried on a graphite rod 13 protected by an alumina sheath 14. A stirrer 6 of molybdenum is carried on an inner steel shaft 7, and the molybdenum cathodes 9 are circular and provided with louvres 10, through which the suspension of UO2 flows impelled by the stirrer. The cathodes are connected to a tungsten rod 11. A suspension of hydrogen-refined UO2 is suspended in molten CaCl2 and this electrolyte is treated at 5-6V. for 2 hours, the stirrer being stopped before the end of the run to ensure reduction of any UO2 resting on the cathode. The product of pure uranium powder is then washed and dried. The UO2 used as starting material is either electrolytic or hydrogen-precipitated; the hydro-precipitated oxide is not satisfactory. In apparatus for making U/Al alloy no stirrer is used, but in the case of U/Fe alloys a stirrer may be employed. Specification 889,307 is referred to.