1、 Ion exchange resin:
1. Definition: Ion exchange resin refers to a resin that uses a copolymer of styrene and divinylbenzene as the skeleton (represented by R), and introduces some active groups (such as sulfonic acid groups, carboxyl groups, and phenolic groups) onto the skeleton, that is, ion exchange resin.
2. Properties: Ion exchange resin has certain mechanical strength, wear resistance, and does not dissolve in water, acid, alkali, or any organic solvents. It has certain chemical stability to general oxidants and reducing agents.
3. Types of ion exchange resins:
According to the acidity and alkalinity of the imported active groups, they are divided into:
(1) Cation exchange resin: R-SO3H, R-COOH, R-OH,
(2) Anion exchange resin: primary amine NH3OH, secondary amine NHOH, quaternary amine NaOH
3) In practical use, there are sodium type resins and chlorine type resins.
For example, strong acidic cationic resins are often reacted with NaCl to convert them into sodium type resins before use. For example, anionic resins can be converted into chlorine type and reused, releasing Cl - during operation while adsorbing and exchanging other anions. Its regeneration only requires a salt solution. Chlorine type resin can also be converted into bicarbonate type (HCO3-) for operation.
  
According to the model:
(1) Strong acid cation exchange resin: Shanghai 730 #, 732 #, Nankai 1 and Yibin 010 type
(2) Strong alkaline anion exchange resin: Shanghai 717 #, 711 #, Nankai, Yibin 201 type