KELATERANDE HARTSER AV GEL-TYP OCH FOERFARANDE FOER AVLAEGSNANDE AV FLERVAERDA JORDALKALIMETALL- OCH TUNGMETALLKATJONER FRAON LOESNINGAR.

摘要

Improved processes for the removal from solution of multi-valent alkaline earth metal and/or heavy metal cations are taught, having excellent combinations of cation capacity and resistance to bead breakage. The processes use specified polymer resin beads functionalized with chelating functionalities such as alkylaminophosphonic moieities or iminodiacetic acid moieites. The beads are prepared by the specified process to have a decreased amount of cross-linking in the shell area as compared to the core. An additional aspect of the invention is an improved gel-type chelating resin having core-shell morphology and alkylaminophosphonic functional groups which is found to exhibit surprising combinations of dynamic capacity, osmotic shock resistance, and physical strength. This chelating resin has been found to be very suitable for the removal of calcium from brine solutions prior to the use of such solutions in membrane electrolysis cells for chlorine production.