Separation of ionic mixtures in sorption columns with two liquid phases
A new approach to the treatment of highly concentrated solutions of electrolytes in ion exchange and sorption columns with zero bed porosity is proposed. The approach concerns reducing the inter-particle space occupied by working solutions in columns by filling them with special organic liquids immiscible with water. By a variety of examples, including the separation of nitric acid and nitrates for processing aluminium concentrates, purification of working electrolytes for copper refining, conversion of potassium chloride into chlorine-free fertilizers etc., the advantages of the proposed method are demonstrated and show that using the new method in ion exchange and acid retardation processes does not affect the equilibrium separation parameters, but significantly improves the kinetics by eliminating longitudinal dispersion effects. Also this makes it possible to reduce the duration of working cycles, thereby raising the efficiency of the use of separation columns.