| abstract |
An illustrative embodiment of the invention converts a feed solution stream into three separate streams of concentrated acid, concentrated alkali and deionized liquid, respectively, through a combination of ion exchange and electrodialysis techniques. Typically, feed fluid from the primary coolant loop of a nuclear reactor that contains ionized boric acid and lithium -7 hydroxide flows into a bed of mixed anion and cation exchange resins. Two of the walls of this bed, however, are of anion permeable and cation permeable membranes respectively, to permit the anions to migrate into an anolyte compartment and to permit the cations to migrate into a catholyte compartment. Within the anolyte compartment there is an anion resin bed which purifies the borate ions from other contaminative anions. Within the catholyte compartment there is a cation resin bed which purifies the lithium ions from other contaminative cations. Appropriately selected anion permeable and cation permeable membranes for the other sides of the catholyte and anolyte compartments, respectively, allow sufficient ion migration to permit a degree of chemcal recombination. The final products from these three flow paths are concentrated boric acid, concentrated lithium hydroxide and deionized water from the respective analyte, catholyte and feed fluid compartments. |