Process for the removal of cations of an alkaline earth metal species from aqueous solutions with an ion exchanger material

摘要

A process for removing cations of a first alkaline earth metal species from an aqueous solution with an ion exchanger material that is a cation exchanger or contains one and subsequently regenerating the loaded or exhausted ion exchanger material. A cation exchanger that has been loaded in advance with cations of a second alkaline earth metal species is used to remove the cations of the first alkaline earth metal species. The cation exchanger that is loaded or exhausted with the first species to be removed is regenerated by bringing the loaded or exhausted cation exchanger into contact with an aqueous suspension of a slightly soluble carbonate and/or hydroxide of the second alkaline earth metal species, either alone or in a mixture with an anion exchanger, and introducing a CO.sub.2 -containing gas into the suspension.