LAMELLAR INORGANIC ION EXCHANGERS Na+-K+-H+ION EXCHANGE IN γ-TITANIUM PHOSPHATE

An equilibrium study of the Na+-K+-H+ ion exchange on γ-titaniura phosphate has been carried out. Isotherms for the ion exchange have been determined and phases formed during the exchange have been identified. Over the entire composition range, the exchanger greatly prefers potassium to sodium. For 0-25% of exchange, the sodium and potassium 25% conversion phases were found to be at equilibrium when the ratio of the sodium-potassium ion concentration of the solution is 30:1. The equilibrium constant is determined and compared with the obtained from the results of the binary systems. For 25-50% of exchange, the H1.5 K0.5 and HK phases co-exist, the small sodium ion concentration in solid phase being in substitution solid solution. When the 50% exchange is reached by the addition of the stoichiometric amount of base, a solid solution of HNaxK1-x formula (with a composition varying with the equilibrium solution composition), is formed. The equilibrium constant for the substitution process Na+ -K+ in the HNaxK1-xphase is determined. A phase diagram of the ternary system is given.