Resin performance and regeneration of ion exchange reaction

1. Exchange Capability

Hydrogen-type cation exchange resin can dissociate hydrogen ions (H +) in water. When encountering metal ions or other cations, mutual exchange occurs, but the exchanged resin is no longer hydrogen-type resin. For example, when the concentration of cations such as calcium ions and magnesium ions in water is quite large, the hydrogen ions in the sulfonic acid type cation exchange resin can be exchanged with calcium and magnesium ions to form a "calcium type" or "magnesium type" The cation exchange resin is as follows: 2R-SO3H + Ca 2+ → (R-SO3) 2Ca + 2H + (calcium-type strong acid cation exchange resin) 2R-SO3H + Mg 2+ → (R-SO3) 2Mg + 2H + (Magnesium-type strongly acidic cation exchange resin) The exchange capacity of the hydrogen-type cation exchange resin is closely related to the valence of the cation to be exchanged. At room temperature, in low-concentration aqueous solutions, the exchange capacity increases as the valence of ions increases, that is, the higher the valence, the greater the tendency for cations to be exchanged.