What is called regeneration of ion exchange resins?
The resin used for a period of time after ion exchange, adsorption of impurities is close to saturation, will be carried out by chemical regeneration treatment, ion adsorption resin and other impurities was removed, so as to restore the original composition and performance. In practice, in order to reduce the cost of regeneration, it is necessary to appropriately control the dosage of regeneration agent, so that the performance of the resin can be restored to the most economical and reasonable regeneration level, and the recovery degree of the control performance is usually from 70 to 80%. If higher levels of regeneration are achieved, the regeneration dose will increase considerably, and the utilization of the recycled agent will decrease.
The regeneration characteristics of resin are closely related to its type and structure. The regeneration of strong acid and strong alkaline resin is difficult. The regeneration dose is much higher than the theoretical value, while the weak acid or weak base resin is easy to regenerate, and the regeneration dose needs only a little more than the theoretical value. In addition, resins with large pass and low cross linking degree are easy to regenerate, while those with gel type and high crosslinking degree have longer regeneration reaction time.The type of recycling agent should be selected according to the ion type of resin, and appropriate choice of lower prices of acids, bases or salts. For example: sodium type strong acid cation resin can be used to regenerate the 10%NaCl solution, 2 times of dosage for its exchange capacity (NaCl 117g/ l resin); hydrogen type strong acidic resin with strong acid regeneration, reaction with sulfuric acid to produce calcium sulfate precipitate with calcium sulfate to prevent by resin adsorption. For this reason, it is better to pass through the dilute sulfuric acid regeneration of 1 ~ 2%.
The regeneration of the resin shall be based on the type and characteristics of the resin, as well as the economy of operation, and the proper regeneration agent and working conditions shall be chosen.
