Zirconium phosphate

Zirconium phosphate ( ambiguous )

White solid

Fixed

3.3 g · cm -3 ( 25 ° C)

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Zirconium (IV) hydrogen phosphate is an inorganic chemical compound of zirconium from the group of phosphates.

Production and representation

In the precipitation of phosphates of zirconium, hafnium or titanium, from hydrochloric acid solutions of the metal salts with phosphate arise gel X-ray amorphous precipitates, the composition approximately the formula M ( HPO4 ) 2 · H2O (M = Ti, Zr, Hf ), corresponding to, but due to the polymeric character depending on the production conditions more or less deviate from it. By a suitable method, however, also crystalline in composition better defined phosphates can be represented (for example Zirconiumorthophosphat ). Of these have been studied in detail because of the cation exchange capacity zirconium phosphates.

Zirconium (IV), hydrogen phosphate can be obtained by reacting zirconium oxychloride octahydrate with phosphoric acid.

Properties

Zirconium ( IV) hydrogen phosphate is a white crystalline solid with a layered structure which is isotypic to the analogous phosphates of titanium, germanium, tin and lead. He loses at 110 ° C reversibly its crystal water and decomposes at 700 ° C to ZrP2O7. In concentrated mineral acids, with the exception of hydrofluoric acid, it is poorly soluble. The layered structure can accommodate a varying number of crystal water ( 0 .2 ) between the layers, thereby changing the spacing of the layers. In the literature (as opposed to the usual nomenclature of modifications ) denotes the α - zirconium phosphate monohydrate, the dihydrate as γ - zirconium phosphate and zirconium phosphate anhydrous and β -. α - zirconium phosphate has a monoclinic crystal structure with space group P21 / c and Z = 4 The dihydrate also has a monoclinic crystal structure.

Use

Zirconium (IV) hydrogen phosphate is used for the preparation of compounds with an organic or inorganic layer structure. α - zirconium ( IV) hydrogen phosphate may be used for the removal of Ca2 and Mg2 ions from solutions. γ - zirconium ( IV) hydrogen phosphate may be used to ion exchange with a phosphate ester.