| 摘要 |
PROBLEM TO BE SOLVED: To make treatment efficiency improve by passing through a zone including the beds of ion exchange substances with different values of temperatures dependent selectivity during two periods of different temperature when a solution enriched with a desired ion is made from a supply solution containing an undesired ion. SOLUTION: Four ion exchange beds A-D as two pairs of series filled with zeolite-X ion exchange substances are formed, the beds C, D are constituted in a low temperature zone, while the beds A, B are constituted in a high temperature zone. Supply brine 101 or 111 is supplied selectively to the joint between two beds, Li<+> rich reflux, or a recycle flow 102, is introduced to the top of the bed A and transferred through the beds A, B, Na<+> rich brine is taken out from the top of the bed C, and part of it is introduced to the bottom of the bed D. Next, Li<+> rich brine is taken out from the top of the bed C while the beds C, D being moved upward. When the purity of a top product 105 begins to decrease, temperature is changed. |
