Uranium chloride, formation

Uranium (V) chloride, formation of, in preparation of uranium (IV) chloride, 5 144... 

Chlorides. The oHve-green trichloride [10025-93-1], UCl, has been synthesized by chlorination of UH [13598-56-6] with HCl. This reaction is driven by the formation of gaseous H2 as a reaction by-product. The stmcture of the trichloride has been deterrnined and the central uranium atom possesses a riine-coordinate tricapped trigonal prismatic coordination geometry. The solubiUty properties of UCl are as follows soluble in H2O, methanol, glacial acetic acid insoluble in ethers. 

It can be shown that the virial type of activity coefficient equations and the ionic pairing model are equivalent, provided that the ionic pairing is weak. In these cases, it is in general difficult to distinguish between complex formation and activity coefficient variations unless independent experimental evidence for complex formation is available, e.g., from spectroscopic data, as is the case for the weak uranium(VI) chloride complexes. It should be noted that the ion interaction coefficients evaluated and tabulated by Cia-vatta [10] were obtained from experimental mean activity coefficient data without taking into account complex formation. However, it is known that many of the metal ions listed by Ciavatta form weak complexes with chloride and nitrate ions. This fact is reflected by ion interaction coefficients that are smaller than those for the noncomplexing perchlorate ion (see Table 6.3). This review takes chloride and nitrate complex formation into account when these ions are part of the ionic medium and uses the value of the ion interaction coefficient (m +,cio4) for (M +,ci ) (m +,noj)- Io... 

The main emphasis was laid, in this initial work, on Haber s catalysts, e.g., osmium and uranium compounds, as well as on a series of iron catalysts. Some other metals and their compounds which we tested are, as we know today, less accessibble to an activation by added substances than iron. Therefore, they showed no improvement or only small positive effects if used in the form of multicomponent catalysts. Finally, the substances which we added to the metal catalysts in this early stage of our work were mostly of the same type as those which had proved to favor the nitride formation, e.g., the flux promoting chlorides, sulfates, and fluorides of the alkali and alkaline earth metals. Again, we know today that just these compounds do not promote, but rather impair the activity of ammonia catalysts. 

Uranium(VI) dioxydichloride, 5 148 Uranium (VI) hydrogen dioxyortho-phosphate 4-hydrate, 6 150 analysis of, 5 151 Uranium(IV) oxalate, 3 166 Uranium (IV) oxide, formation of, by uranyl chloride, 6 149 Uranium (IV) (VI) oxide, U3Oa, formation of, by uranyl chloride, 5 149... 

Fundamental studies have been reported using the cationic liquid ion exchanger di(2-ethylhexyl) phosphoric acid in the extraction of uranium from wet-process phosphoric acid (H34), yttrium from nitric acid solution (Hll), nickel and zinc from a waste phsophate solution (P9), samarium, neodymium, and cerium from their chloride solutions (12), aluminum, cobalt, chromium, copper, iron, nickel, molybdenum, selenium, thorium, titanium, yttrium, and zinc (Lll), and in the formation of iron and rare earth di(2-ethylhexyl) phosphoric acid polymers (H12). Other cationic liquid ion exchangers that have been used include naphthenic acid, an inexpensive carboxylic acid to separate copper from nickel (F4), di-alkyl phosphate to recover vanadium from carnotite type uranium ores (M42), and tributyl phosphate to separate rare earths (B24). 

Examples of this analysis mode are presented in Fig. 5. The slope of the log D versus log[L],i plots for the cobalt(II)-8 M HCl and the Fe(III)-6 M HCl systems indicate the formation of CoClj and FeClj, respectively, as the predominant complexes in the Dowex 1-X8 phase. These results are believed to prove the reliability of this approach, the presence of these complexes in concentrated hydrochloric acid being well documented. The chloride complex of uranium(IV), UClj, v 4iose unique absorption spectrum is shown in Fig. 6 [11], in the HCl, HCIO4 (I = 10 M)... 

Molybdenum(VI) sorption was achieved on Sephadex G-10 at pH 2.5 in ammonium chloride solutions by the formation of a M0-NH3-glucose complex Alkali- and alkaline earth metal traces remained quantitatively in the effluent and were determinable with a coefficient of variation of 10% up to 60 ppm, and 5% at above 60 ppm. Uranium was separated from rare-earth elements using a cellulose column and an ether-nitric acid separation procedure... 

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