There are many varieties of ion exchange resins, which have different functions and properties due to different chemical compositions and structures, and are suitable for different purposes. Appropriate types and varieties of application resins should be selected according to process requirements and material properties.
In general, the following points need to be paid attention to during use:
1.The ion exchange resin contains a certain amount of water and should not be stored in the open air. It should be kept moist during storage and transportation to avoid air-drying and dehydration, which will break the resin. If the resin is dehydrated during storage, it should be soaked in concentrated salt water (10%) first. Then gradually dilute it, do not put it directly into water, so as to prevent the resin from rapidly expanding and breaking.
2. During storage and transportation in winter, it should be kept in a temperature environment of 5-40 °C to avoid overcooling or overheating, which will affect the quality. If there is no insulation equipment in winter, the resin can be stored in salt water. The concentration of salt water can be adjusted according to the temperature. Depends.
3. Industrial products of ion exchange resins often contain a small amount of low polymers and unreacted monomers, as well as inorganic impurities such as iron, lead, copper, etc. When the resin is in contact with water, acid, alkali or other solutions, the above The substance will be transferred into the solution and affect the quality of the effluent. Therefore, the new resin must be pretreated before use. Generally, the resin is fully expanded with water. Then, the inorganic impurities (mainly iron compounds) can be used for 4-5 % dilute hydrochloric acid to remove, organic impurities can be removed with 2-4% dilute sodium hydroxide solution, and wash until nearly neutral. If used in pharmaceutical preparation, it must be soaked in ethanol.
4. During the use of the resin, avoid contact with metal (such as iron, copper, etc.) oil stains, organic molecular microorganisms, strong oxidants, etc., so as not to reduce the ion exchange capacity or even lose its function. Activation treatment, the activation method can be determined according to the pollution situation and conditions. Generally, the cation resin is susceptible to Fe pollution during softening. It can be soaked in hydrochloric acid, and then gradually diluted. The anion resin is susceptible to organic pollution. 10%NaC1+2-5%NaOH can be used The mixed solution can be soaked or rinsed. If necessary, it can be soaked in 1% hydrogen peroxide solution for a few minutes. Others can also be treated by acid-base alternation, bleaching, alcohol and various sterilization methods.
5. Pretreatment of new resins: The industrial products of ion exchange resins often contain a small amount of oligomers and unreacted monomers, as well as inorganic impurities such as iron, lead, and copper. When the resin is in contact with water, acid, alkali or other solutions, the above substances will be transferred into the solution and affect the quality of the effluent. Therefore, new resins must be pretreated before use. Generally, the resin is swelled with water first, and then the inorganic impurities (mainly iron compounds) can be removed with 4-5% dilute hydrochloric acid, and the organic impurities can be removed with 2-4% dilute sodium hydroxide solution and washed to near neutrality
