D408 chelating resin with iminodiacetic acid-based chelating gene, the metal ion selectivity similar to EDTA, selective order: Hg> Cu> Pb> Ni> Cd> Zn> Co> Mn> Ca> Mn> Ca> Mg> Ba> Sr> Na When the solution of the CPC there are monovalent and divalent metal ions chelate resin selectively D408 divalent metal ion exchange adsorption, showing the high selectivity of the divalent metal ion, a high affinity. At the same time, the divalent metal ion exchange adsorption in the low PH value of the solution easily desorption (regeneration) the chelate gene resume function of the exchange adsorption, excellent chemical properties, confers D408 chelation the resin has repeated applications and a wide range of uses. D408 chelating resin main physical and chemical properties: The resin matrix: macroporous styrene - divinylbenzene copolymer sphere. Chelating functional genes: iminodiacetic acid base {-CH2N-(CH2NCOONa) 2} Exchange capacity: ≥ the 0.6mmolml-R-Na (Cu2 + dynamic method) Stability: pH, organic solvent stability requirements for refined secondary brine no free chlorine. Appearance: light yellow to gray-brown opaque spherical particles. Wet apparent density: 0.70 to 0.80 g / m Wet true specific gravity: (20 ° C): 1.10 to 1.20 Particle size range: 0.30 to 1.20mm The valid particle size: 0.35 to 0.55mm Uniformity coefficient: <1.7 Moisture content: 50 to 62% PH: refined secondary brine 9.0 ± 0.5, for the recovery of metal ions varies. Volume change: in water: R-H/R-Na = 0.75 Degree of swelling: <25% Factory pattern: Na type