Uranyl sulfato complexes

More then 150 minerals containing uranium are known. Typically, however, uranium ores contain only about 0.1% uranium. In the commercial production of uranium metal, the ore is crushed, concentrated, roasted, and in most cases leached with sulfuric acid in the presence of an oxidizing agent such as manganese dioxide or chlorate ions to convert all of the uranium to uranyl sulfato complexes. Carbonate leaching is used to extract uranium from ores containing minerals such as calcite. The recovery of uranium... 

Sulfates and sulfites. Mono- and bis-sulfate complexes of actinyl ions, An02S04 and An02(S04)2 , are generally prepared from acidic solutions. The geometry about the actinide metal center is pentagonal biypyramidal from actinyl, sulfato, and aquo oxygen atoms. A tris(sulfato) complex has been reported, but it is very weak if it does exist. Ternary hydroxo, sulfato complexes have been reported for uranyl, but they have not been structurally characterized. 

Ion Excha.nge, The recovery of uranium from leach solutions using ion exchange is a very important process (42). The uranium(VI) is selectively adsorbed to an anion-exchange resin as either the anionic sulfato or carbonato complexes. In carbonate solutions, the uranyl species is thought to be the tris carbonato complex, U02(C03) 3 [24646-13-7] and from sulfate solutions the anion is likely to be U02(S0 , where nis ) [56959-61-6] or 2 [27190-85-8], The uranium is eluted from the resin with a salt or acid solution of 1 AfMCl or MNO (M = H", Na", The sulfate solution is... 

The 0x0 (0 ) ligand is dominant in the coordination chemistry of osmium, participating in the VIII to IV oxidation states inclusive. The tetroxide OSO4 is the single most important compound of osmium OSO4 and the recently discovered [0s04] ion arc tetrahedral. The /ra 5-[0=0s —O] osmyl moiety displays an extensive chemistry, comparable with that of the uranyl 0=U=0 unit, and there is an extensive and unique cyclic oxo-ester chemistry (p. 584). There is surprisingly little information on hydroxo, aqua, sulfato, nitrato or phosphato complexes, but much recent work has been carried out on carboxylato species, and clearly much work remains to be done on the O-donor chemistry of the element. There are a reasonable number of sulfur-donor complexes but few with selenium or tellurium. 

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