METHOD OF ISOLATING SODIUM IODATE FROM AQUEOUS SOLUTIONS Russian patent published in 1998 - IPC

FIELD: drilling fluids. SUBSTANCE: invention aims at recovering iodine from drilling muds. Method includes formation of solid phase in solution by way of successively cooling solution to a temperature below 0 C, which causes crystallization of ice with linear crystallization velocity 0.4-2.2 mm/h to attain ice volume constituting 10-50% of initial solution volume. Ice is separated from non-crystallized part of solution and melted at temperature as high as 20 C to separate sodium iodate precipitated from solution formed on melting. It is advisable, to initial solution containing sodium iodate in concentration below eutectic concentration, to add an extra component easily soluble in water and containing ion common with component to be separated (e.g. NaI) at ratio of extra component to component being separated (3-5):1. EFFECT: facilitated iodate separation. 2 cl