Calcium uranate

Calcium Uranate, CaUO, and calcium diuranate, CaUaO , are similar to the corresponding barium salts and may be prepared by similar methods. The diuranate is highly refractory and does not fuse at red heat. 

CaU04 CALCIUM URANATE 474 CeBr3[g] CERIUM BROMIDE (GAS) 511... 

Strontium Uranate, SrUOi, and strontium diuranate, SrU207, are similar in properties and are prepared by similar methods to the corresponding barium and calcium salts. 

The dihydrate is formed by evaporation at ordinary temperature of an ethereal solution of the hexahydrate which has been dried with calcium nitrate or by crystallisation of the hexahydrate from concentrated nitric acid solution. It yields small lustrous plates, thick and square, probably rhombic, and possessing a green fluorescence. It melts at 179-3° C. It is much more stable than the trihydrate, and can be kept in a vacuum desiccator with caustic alkali or i hosphorus pentoxide without any loss of water. It dissolves readily in ether. If the dihydrate is heated in a current of carbon dio.xide at 98° C. a product corresponding very nearly in composition to the nioiiohydrate, U03(N03)3.H20, is obtained at 160° C. under the same conditions the ankydi ffus salt, U02(N03)2, is obtained. The latter may also be obtained by passing a current of dry nitric anhydride over the tri-hydrate carefully heated at 170° to 180° C. It is a yellow amorphous powder, readily soluble in water with c -olution of heat. It reacts violently with ether. When heated to 200° C. it decomposes and leaves a mixture of uranic acid, UO3.H2O, and uranic anhydride. ... 

A large number of inorganic layer crystals such as micas, sodium silicates, niobate, uranate, vanadate, titanate, zirconium phosphate, graphitic acids, crystalline silicic acids, vanadium oxyhydrate, calcium phosphoric acid esters, and titanium disulfide develop alkyl crystals between their rigid crystal layers by ion exchange with, for example, alkyl ammonium salts and by intercalation inorganic... 

Ovcharenko, Y. K., and Kurishko, V. A. (1971). Characteristics of Calcium Chloride Brine Trapped in the Melovyy Uplift in the Crimean Steppe. Uran. Nauch.-lssl. Geol. Inst., Trudy 26, 182-190. 

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