Ion-exchange properties of zirconyl phosphates—III

Precise determination of Rb, Sr, Ba, and Pb in geological materials by isotope dilution and ICP-quadrupole mass spectrometry following selective separation of the analytes

“…The very high selectivity of many inorganic cation exchangers for the heavy alkali metals Cs and Rb was documented several decades ago. [20][21][22] In particular, the ion exchange properties of microcrystalline zirconium and titanium phosphates have been used in column separation of the alkali metals, based on the affinity series Na 1 v K 1 % Rb 1 v Cs 1 (e.g., ref. 22).…”

“…[20][21][22] In particular, the ion exchange properties of microcrystalline zirconium and titanium phosphates have been used in column separation of the alkali metals, based on the affinity series Na 1 v K 1 % Rb 1 v Cs 1 (e.g., ref. 22). These materials have been widely used in the field of nuclear chemistry, by virtue of their good irradiation and thermal stability compared to ion-exchange resins.…”

Cation Exchange and Sorption Properties of Crystalline α-Titanium(IV) Phosphate

“…Crystalline titanium phosphate in the alpha form, namely Ti(HPO 4 ) 2 · H 2 O (α-TiP), which belongs to the family of lamellar materials, presents an interesting behavior as ionic exchanger and is considered an excellent matrix for the known intercalation process (1). It has been used in the separation of radioactive Cs from strongly acidic, nuclear-fuel reprocessing solutions (11), in separations of Curie-level activities of 228 Th and 227 Ac from traces of 226 Ra (12), and in the thin-layer chromatographic separations of Na from K (13). α-TiP seems especially attractive when the ion-exchange process has to take place in intense radiation fields, as in the case of reactor coolant water being treated to remove corrosion products (14).…”

Mechanism of ion exchange in zirconium phosphates. 28. Calorimetric determination of heats of rubidium(1+)-hydrogen ion exchange on .alpha.-zirconium phosphate

“…The Rb+-H+ exchange reaction on crystalline -ZrP is not reversible so that it is not legitimate to derive equi- librium constants. However, following a procedure previously invoked for Na+-H+ exchange,15 one can think of the first part of the ion exchange reaction as being ideally 2/3HH-H20 + Rb+ + nH20 2/3H0.5RbL5(1.5n + 1)H20 + H+ (9) = aRbaH+/OHCtRb+aWn (10) In the range 0-75% of Rb+ loading one solid of constant composition is converted to another of constant composition. If we choose as the standard reference state an activity of 1 for the ions in the pure solids, we get ^rI^H = aH+/flRb+aWn (11) where the equilibrium constant is expressed per mole of Rb+.…”