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Regeneration of ion exchange resins
Source: | Author:佚名 | Publish time: 2019-05-15 | 97 Views | Share:
After the use of ion exchange resin for a period of time, adsorption of impurities close to saturation, it is necessary to regenerate treatment, with chemicals to the resin adsorption of ions and other impurities removed, so that it restores the original composition and performance.

After the use of ion exchange resin for a period of time, adsorption of impurities close to saturation, it is necessary to regenerate treatment, with chemicals to the resin adsorption of ions and other impurities removed, so that it restores the original composition and performance. In practical application, in order to reduce the cost of regeneration, it is necessary to properly control the amount of regenerative agent, so that the performance of the resin to the most economical and reasonable regeneration level, usually control the degree of recovery of the performance of 70~80%.


If a higher level of regeneration is to be achieved, the regenerative dose will increase substantially and the utilization rate of the regenerator will decrease. 

  The regeneration of the resin shall be based on the type and characteristics of the resin, as well as the economic nature of the operation, the selection of appropriate regenerative agents and working conditions. The regeneration characteristics of the resin are closely related to its type and structure. The regeneration of strong acidic and strong alkaline resin is difficult, and the regenerative dose is much higher than the theoretical value, while the weak acidic or weak alkaline resin is easier to regenerate, and the regenerative dose used is only slightly more than the theoretical value.


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In addition, the resin with low pore type and crosslinking degree is easier to regenerate, while the resin with high gel type and crosslinking degree has a longer regeneration reaction time. The type of regenerative agent should be selected according to the ion type of the resin, and the lower price of acid, alkali or salt should be selected appropriately. For example: sodium strong acidic cationic resin can be regenerated with 10%NaCl solution, the amount of medication is twice times its exchange capacity (with NaCl amount of 117g/l resin), hydrogen type strong acidic resin regenerated with high acid, sulfuric acid to prevent the resin adsorption of calcium and sulfuric acid reaction to produce calcium sulfate sediment.


For this reason, it is advisable to first enter the 1~2% of dilute sulfuric acid regeneration. Chlorine strong alkaline resin, mainly to NaCl solution to regenerate, but the addition of a small amount of alkali to help the resin adsorption of pigment and organic matter dissolved and washed out, so usually the use of 10%NaCl + 0.2%NaOH alkali Salt liquid regeneration, the conventional dosage for each liter of resin 150~ 200g NaCl, and 3~4g NaO H.    OH type strong alkali anion resin is regenerated with 4%NaOH solution. The chemical reaction of resin regeneration is the inverse reaction of the original exchange adsorption of resin. According to the principle of chemical reaction equilibrium, increasing the concentration of the substance of one side of chemical reaction can promote the reaction to the other side, so increasing the concentration of regenerative fluid can accelerate the regeneration reaction and reach a higher level of regeneration.