Calcium ion exchange behavior of Zeolites used in detergent such as NaA, NaX and NaP was studied by Ion Selective Electrode Method (ISE). The linear relationship between calcium ion exchange capacity and framework aluminum content of zeolite NaX was found, and the effects of exchange temperature, concentration of zeolite and other cations on calcium ion exchange behavior were also investigated. The sequence of the calcium ion exchange selectivity of zeolite MAP, NaA and NaP was determined. The framework structure of zeolite NaA, NaX and NaP significantly influence the cation exchange behavior of these three zeolites.
Exchange rates of calcium ion with high aluminum zeolites used in detergent, such as NaA, MAP and MAX zeolites, were measured by using a improved calcium ion selective electrode method (ISE). The calcium exchange kinetics of zeolites was studies by using Body Reichenberg diffusion equation. The effects of the particle size, pore structure of zeolites and the ion exchange temperature on the calcium ion exchange kinetics were also investigated. Results showed that the diffusion coefficients at room temperature were 2.33×10-15m2·s-1, 4.28×10-16m2· s-1 and 7.73×10-17m2·s-1 for zeolite MAX, NaA and MAP, respectively. The activation energy of diffusion was 48kJ·mol-1, 65kJ·mol-1 and 91kJ·mol-1 for zeolite MAX, NaA and MAP, respectively.
