Calcium removal method

摘要

In accordance with the present invention, there is provided a calcium removal method capable of reducing operation cost. A solution L2 containing potassium or/and sodium, and calcium is passed through an ion-exchange resin 35 to separate the solution into a solution containing potassium or/and the sodium, and a solution containing calcium. Operation cost can remarkably be decreased since potassium carbonate is not required to remove calcium as before. Timing for changing a calcium-containing water L3 and a salt water L4 discharged from the ion-exchange resin can be performed based on at least one measurement result selected from the group consisting of: a calcium or chlorine concentration; electrical conductivity; and pH of a fluid which is discharged from said ion-exchange resin. The solution may be a filtrate L1 that is obtained by washing a chlorine bypass dust D generated in a cement burning process, or a leachate W of a final disposal site 50.

主权项

1. A method of removing calcium from a solution containing potassium or/and sodium, and calcium using water and an ion-exchange resin to separate said solution containing potassium or/and sodium, and calcium into a solution containing potassium or/and the sodium and a solution containing calcium, wherein the method comprises the steps of:
(a) providing an amphoteric ion-exchange resin filled up with said water; (b) introducing the solution containing potassium or/and sodium, and calcium into the amphoteric ion-exchange resin; (c) introducing said water for regenerating the amphoteric ion-exchange resin; (d) discharging the solution containing potassium or/and sodium from the amphoteric ion-exchange resin; (e) discharging the solution containing calcium from the amphoteric ion-exchange resin separate from the discharging in step (d) so as to separate the solution containing potassium or/and sodium from the solution containing calcium; and (f) repeating steps (b) to (e).