Sodium zirconium phosphate

The properties and behavior of double phosphates such as — Y)3 (216), sodium—zirconium phosphate—siUcates (217), and... 

Sheetz, B. E., Agrawal, D. K., Breval, E. Roy, R. 1994. Sodium zirconium phosphate (NZP) as a host structure for nuclear waste immobilization A review. Waste Management, 14, 489-505. 

PHOSPHATE WASTE FORMS SYNTHETIC PHASES Sodium zirconium phosphate (NZP)... 

Sodium hydrogen zirconium phosphate [34370-53-17 is an ion-exchange material used in portable kidney dialysis systems which regenerate and reckculate the dialysate solution. The solution picks up urea during the dialysis. The urea reacts with urease to form ammonia, which is absorbed by the sodium hydrogen zirconium phosphate. 

The main interest in zirconium phosphates relates to their ion-exchange properties. If amorphous zirconium phosphate is equiUbrated with sodium hydroxide to pH 7, one hydrogen is displaced and ZrNaH(P0 2 3H20 [13933-56-7] is obtained. The spacing between the zirconium layers is increased from 0.76 to 1.18 nm, which allows this phosphate to exchange larger ions. 

The gels precipitated as described above are not useful in ion-exchange systems because their fine size impedes fluid flow and allows particulate entrainment. Controlled larger-sized particles of zirconium phosphate are obtained by first producing the desired particle size zirconium hydrous oxide by sol—gel techniques or by controlled precipitation of zirconium basic sulfate. These active, very slightly soluble compounds are then slurried in phosphoric acid to produce zirconium bis (monohydrogen phosphate) and subsequently sodium zirconium hydrogen phosphate pentahydrate with the desired hydrauhc characteristics (213,214). 

The zirconium phosphate, a-ZrP, behaves as an ion exchanger where both hydrogen ions of the orthophosphate groups are exchangeable with sodium, potassium, and ammonium in two stages [109], It has an exchange capacity of 6.64 mequiv/g [111],... 

Sodium phosphate solution white precipitate of zirconium phosphate, Zr(HP04)2 or Zr0(H2P04)2, even in solutions containing 10 per cent sulphuric acid by weight and also tartrates and citrates. No other element forms an insoluble phosphate under these conditions except titanium. The latter element can be kept in solution as peroxotitanic acid by the addition of sufficient hydrogen peroxide solution, preferably of 100-volume strength, before the sodium phosphate is introduced. 

Hydrogen peroxide white precipitate of peroxozirconic acid, HOO-Zr(OH)3, from slightly acid solutions this liberates chlorine when warmed with concentrated hydrochloric acid. When both hydrogen peroxide and sodium phosphate are added to a solution containing zirconium, the precipitate is zirconium phosphate (see reaction 3). 

Manganese dioxide, sodium nickel hexacynaoferrate, hydrous titanium oxide, zirconium phosphate, ferric hydroxide, different commercial sorbents... 

Insoluble salts, for example, hydrous zirconium phosphate Heieropolyacids, for example, tanmonium phosphomolybdale Complex ferrocyanides, for example, sodium copper cyanoferrale (II)... 

Anhydrous zirconium phosphate (P04/Zr = 2) and the dihydrate are prepared by adding 100 ml of 1 ilf zirconium oxychloride 8H20 dropwise to constantly stirred, refluxing phosphoric acid solution prepared by dissolving two moles of sodium dihydrogenphosphate H2O in 200 ml of 3 ilf HCl. The zirconium phosphate gel is refluxed in its mother liquor for 25 hours and then washed until free of chloride. When air-dried, the dihydrate or y phase was obtained when vacuum-dried over calcium sulfate, the anhydrous a phase was obtained 117). 

Birch WD, Bring A, Bevan DJM, Khaiisun (1994) Wycheproofite a new hydrated sodium aluminum zirconium phosphate frmom Wycheproof, Victoria, Australia, and a new occurrence of kosnarite. Mineral Mag 58 635-639... 

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... 

Wide-line and n.m.r. measurements led to a value of 1.87 A for the H P distance in Zr(HP04)2 values for all other H H distances are also given. The ion-exchange behaviour of ctystalline zirconium phosphates depends on the method of preparation, and the details of the sodium-potassium exchange on this material have been investigated by two groups. The ion-exchange properties of chromium phosphates similarly... 

Phenol-formaldehyde resin Sodium sulfate Zirconium phosphate acid form ion exchange columns Ammonium phosphomolybdate ion exchange material Cellulose... 

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