Ion Exchange:

In ion exchange, there is an exchange of ions, cations or anions, among an insoluble solid material and the solution in contact along with it. The solid material known as ion exchanger carries exchangeable cations and anions. While the exchanger is within contact along with an electrolyte, these ions could be exchanged for a stoichiometrically equal amount of other ions of same charge. Carriers of exchangeable cations are known as cation exchangers and carriers of exchangeable anions as anion exchangers. Many materials are capable of both cation and anion exchange and are known as amphoteric exchangers. Commonly, ion exchange is performed in columns. Therefore, in a few cases, batch operations are carried out. An extremely special case of ion exchangers is chelating resins. These resins contain functional groups that are chelating ligands. They form multiple bonds along with complex creating metal ions. These resins have much higher affinities for transition metal ions than for alkali metal ions.