Abstract: Due to the largest adsorption capacity to calcium ions，chelating resin LSC-500 was chosen as the optimum adsorbent after comparing with D152，D401，D418，001×7, and 001×14.5 resins.The static adsorption experiments were carried out to absorb calcium ions in the potassium?鄄rich solution.Experiment results showed that the saturated adsorption capacity of calcium ion was found to be 23.42 mg/g at 25 ℃.The optimum conditions for removing Ca²⁺ were：the reaction time was 180 min and the adsorption temperature was 65 ℃.Under the conditions，the removal rate of calcium ions with LSC-500 resin was 92.86%.Through the dynamic experiment, kinetic curve of resin absorbing calcium ions was obtained，and the absorption kinetics data were fitted by liquid film diffusion model and intra-particle diffusion model respectively.Dynamic experiment results showed that increasing temperature was good for the adsorption process，and the liquid film diffusion was the main rate-control step of absorbing calcium ions by chelating resin LSC-500.

Key words: adsorption, chelating resin LSC-500, calcium ion, kinetics