DIAION™ CR11 has iminodiacetic acid group as chelating ligand which is bonded onto a highly porous crosslinked polystyrene matrix. DIAION™ CR11 shows large affinity for alkaline earth and transition metal ions, and the selectivity is similar to that of ethylene diamine tetra-acetic acid (EDTA).
The selectivity order of DIAION™ CR11 for metal ions is as follows:
Adsorbed metal ions can be eluted with an acid, and the resin can be reused after regeneration with caustic alkali.
The most typical application of DIAION™CR11 is the secondary purification of brine in Chlor-soda electrolysis plants. DIAION™ can remove a small number of alkaline earth metals (Ca2+, Mg2+, St2+) from a highly concentrated sodium chloride solution.