Process for the removal of electrolytically dissociated salts present in small amounts from concentrated solutions of other dissociated salts

摘要

According to the invention, electrolytically dissociated salts present in small amounts are removed from solutions which contain other electrolytically dissociated salts at high concentration. For this purpose, the solution is passed to a prepared exchanger bed, whose counterions have previously been equilibrated with those of the solution and the bed washed out with water. During the feeding of this solution, the bed takes up counterions and co-ions of both groups as a result of absorption, the quantities taken up being established in accordance with the Donnan equilibrium. According to the invention a second solution is now passed through the bed, which solution only contains those counterions which are contained in the first solution at high concentration, and the co-ions. This solution removes from the exchanger bed the quantity of the other counterions taken up by it. Subsequently, water is applied to the bed, which displaces the second solution from the bed, which solution only contains those ions which were present in the first solution at high concentration. Part of this outflow is stored and used again in the next process cycle and another part is passed out as the product of the process.