Uranium chlorides

Action of chlorine on uranium oxide to recover volatile uranium chloride Removal of iron oxide impurity from titanium oxide by volatilization hy action of chlorine... 

Uranium carbonates, 25 430-432 Uranium chlorides, 25 438-439 Uranium compounds, 25 421-434 handling, 17 529 Uranium dioxide, 25 422-423 Uranium-enrichment process gas centrifuge, 25 413-415 Uranium exploration, 25 398 URanium Extraction (UREX) process, 25 420... 

Uranium Arsenide, U3As4, may be obtained i by passing hydrogen over a fused mixture of sodium uranous chloride and sodium arsenide. It is a greyish powder which readily burns in the air. Sometimes it is obtained in a pyrophoric condition. An aluminium-containing product results when the aluminothermic process, using an oxide of uranium and arsenious oxide, is employed. The purest arsenide is obtained, in the crystalline form, when a mixture of hydrogen and arsenic vapour is passed over sodium uranium chloride. It is rapidly decomposed by nitric acid. 

Table 10.7 Melting points and boiling points of uranium chlorides...

Although there are a number of reported methods for preparing uranium hexachloride, most of them can be grouped under two types.(1) Uranium hexachloride can be prepared by further chlorination of lower uranium chlorides. This type includes those preparations in which a uranium oxide is the starting material, since a lower uranium chloride is normally formed as an intermediate in these chlorination reactions. (2) Uranium hexachloride is formed in the thermal decomposition of uranium pentachloride. Neither method yields uranium hexachloride in a very pure form. Uranium/chlorine ratios of 1 5.8 to 5.9 are normally the best encountered. 

Electrolytic Methods.—Moissan obtained the metal by electrolysis of the double sodium uranium chloride in an atmosphere of hydrogen, using carbon electrodes. Feree, by electrolysis of an aqueous solution of uranous chloride, using a mercury cathode, obtained a uranium amalgam, from which he isolated the uranium by distilling off the mercury in vacuo. However, uranium cannot be obtained in any quantity by this means. 

Pollok has investigated the sjiark spectrum of a solution of uranium chloride, with a view to determining the most jjersisfenf lines, and records his results as follows ... 

Uranium Sesquiselenide, UaSCg, is formed when a current of hydrogen mixed with a small proportion of selenium vapour is passed rapidly over the double sodium uranium chloride, Na2U4Clg, at 1000° C. ... 

Uranium Tellurlde, UgTej.—This is the only compound of uranium and tellurium the existence of which is definitely established. It is formed when hydrogen containing tellurium vapour is passed over the double sodium uranium chloride at 1000° C., or when the chloride is heated with sodium telluride in hydrogen at the same temperature. ... 

Non-aqueous Process. A halide volatility process has been extensively studied among the dry reprocessing processes. The chloride distillation using carbon tetrachloride has been studied in applying to the treatment of irradiated uranium dioxide (32). In a proposed flow-sheet, chlorination and distillation processes are followed by the sorption and desorption process of uranium chloride on a barium chloride bed. Fundamental data of decontamination for the fission products have been accumulated, showing that excellent purification of uranium is achieved. 

Uranium is deposited on the negative electrode in the electrorefining phase of fuel reprocessing. The crystalline mass is about 97% LiCl and KCl. The remaining 3% uranium chloride is responsible for the amethyst color. 

UOCI URANIUM CHLORIDE OXIDE 1750 WCI[g] TUNGSTEN CHLORIDE (GAS) 1791... 

IV. Many variations of the reaction of uranium chlorides with metallic Na in sealed iron vessels have been described. The products range in purity from 99 to 100% U. The preparative method described below is based on the earlier procedures and attempts to overcome some of their shortcomings however, it affords a uranium whose x-ray diffraction pattern still clearly shows UO 3 lines. For this reason one must question the assertions of earlier authors who claimed that this procedure gives a completely pure product. 

I. The preparation of completely pure UCU (or UCls) is difficult since under normal conditions there exists an equilibrium 2 UCU + CI3 = 2 UCI5. However, for many purposes, especially for the subsequent reduction to metallic U, any mixture of the two uranium chlorides is adequate. Such a mixture is prepared rapidly and conveniently by the following method. 

It was only in 1841 that the French chemist E. Peligot succeeded with the aid of a new reduction method. He heated anhydrous uranium chloride mixed with metallic potassium in a closed platinum crucible and obtained a black metallic powder. Its properties noticeably differed from those which M. Klaproth used to ascribe to metallic uranium. Therefore, some historians of science associate the real discovery of uranium with the name of E. Peligot. 

B is also intended to keep the plastic bottle and to ship uranium chloride solutions in it. 

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