Ion exchange resin is a high molecular compound, so its performance varies with manufacturing process, raw material formula, polymerization temperature, crosslinking agent, etc. its main performance is divided into two parts.

(1) Physical properties

① Appearance resin is a kind of transparent or translucent material, which has different colors due to its different composition. For example, styrene resin is yellow, and some are black and Auburn, but it has little impact on performance. Generally, there are many impurities in raw materials or cross-linking agents, and the color of the resin is slightly darker (but the color of the resin sometimes changes due to various reasons during operation). The shape of the resin is spherical, and the spherical rate is required to reach more than 90%.

② Particle size the size of resin particles will affect the exchange rate, pressure loss, backwashing effect, etc. The particle size should not vary too much. The particles of ion exchange resin for water treatment should be 20 ~ 40 mesh. The particle size is expressed by effective particle size and non-uniformity coefficient.

③ The density is related to the water treatment process and resin loading. The expression methods of density include: dry true density (generally about 1.6g/cm3), wet true density (generally between 1.04 and 1.30g/cm3), and apparent wet density (generally between 0.60 and 0.80g/cm3).

④ Moisture content the greater the moisture content of the resin, the greater the porosity and the smaller the crosslinking degree.

⑤ The swelling rate is related to the degree of crosslinking, active groups, exchange capacity, electrolyte density in water, and the properties of exchangeable ions. The resin will swell and shrink in the process of exchange and regeneration, and the resin subject to repeated swelling and shrinking is easy to break.

⑥ The abrasion resistance reflects the mechanical strength of the resin. It shall ensure that the annual resin consumption does not exceed 7%.

⑦ The low polymer contained in the soluble resin shall be gradually dissolved, and colloidal solution will also occur during the use of the resin.

⑧ The heat-resistant cation resin can withstand about 100 ℃, the strong alkali anion resin can withstand 60 ℃, and the weak alkali anion resin can withstand 80 ℃. However, when the temperature is lower than or equal to 0 ℃, it is easy to freeze and break.

⑨ Conductive dry resin does not conduct electricity, while wet resin can conduct electricity.

(2) Chemical properties

① The exchange reaction of ion exchange resin is reversible, so it can be exchanged, regenerated and reused.

② Acid and alkaline. The properties of h+ type cation exchange resin and oh- type anion exchange resin are the same as those of electrolyte acid and alkali. They can ionize h+ and oh- in water.

③ It has neutralization and hydrolysis properties. Because of its electrolyte properties, it can neutralize with acids and bases and also hydrolyze.

④ Ion exchange resins have different ability to adsorb various ions and have selectivity.

⑤ Switching capacity. Indicates the amount of ion exchanged. According to the form of resin, it can be divided into balance exchange capacity, full exchange capacity, working exchange capacity, etc.