The production process of ion-exchange membrane caustic soda is to precipitate alkaline earth metal ions from the original salt or brine with double alkali. After microfiltration membrane filtration, the chelating resin tower is used for secondary refining to remove Ca2+ and Mg2+ in the brine with high precision, and then electrolyze the secondary refined brine to produce high quality ion-exchange membrane caustic soda with higher purity compared with metal anode method.
However, the industrial salt and brine used in the production process of ion-exchange membrane caustic soda contain a certain amount of iodide, which results in the brine containing iodine. The reduction potential of iodine is much lower than that of chlorine, so that iodine can be oxidized prior to chlorine at a lower concentration. Iodate is formed in the anode chamber and deposited on the surface of the ion membrane, which reduces the effective area of the ion membrane. And reduces the current efficiency of the electrolytic cell. In addition, the iodine ion in brine of ion-exchange membrane caustic soda process will accumulate for a long time, resulting in serious iodine exceeding the standard in every process from primary brine to electrolysis. The higher the coexisting content of iodine ion and other ions in brine, the faster the current efficiency decreases, it has become a common subject faced by the majority of ion-exchange membrane caustic soda production enterprises.
Both iodine and chlorine are halogen elements with similar properties, so it is very difficult to separate them. Aiming at this common problem faced by the production of ion membrane caustic soda, Sunresin, as one of the ion exchange resin suppliers, has established a special technology research and development team led by resin product development and application process development, and successfully developed Seplite® LSC285 special resin for brine iodine removal, and developed a complete set of iodine removal process through the industrial scale verification of many domestic ion membrane caustic soda production enterprises, the effect is remarkable. The iodine is effectively removed and the iodine recovery is realized. It not only solves the problem of electricity efficiency, but also creates economic benefits, which is highly praised and recommended by industry and enterprises.
Performance advantages of Sunresin Seplite® LSC285 iodine adsorption resin and complete set of iodine removal process:
(1) The process is mature and the treatment effect is stable and reliable.
(2)It has high selectivity and can realize the precision adsorption removal and recovery of iodine in brine.
(3)The process operation is simple and the operation consumption is low.
(4)The resin treatment capacity is large and the regeneration cycle is long.