Method of regenerating ion exchange resin
A method of regenerating an ion exchange resin, comprising the steps of packing a used ion exchange resin in a regeneration tower; and repeating at least twice a step comprising passing an aqueous solution of regenerant through the regeneration tower downward from a top part of the regeneration tower and thereafter passing ultra-pure water through the regeneration tower upward from a bottom of the regeneration tower. This method enables regenerating an ion exchange resin efficiently and homogeneously without mixing of the regenerant into ion exchange resin towers for purification.
1. A method of regenerating an ion exchange resin, consisting of the steps of:
packing a used ion exchange resin in a regeneration tower; and
sequentially repeating, at least twice, a step consisting of passing an aqueous solution of regenerant through the regeneration tower downward from a top part of the regeneration tower and thereafter passing ultra-pure water through the regeneration tower upward from a bottom of the regeneration tower.
2. The method as claimed in claim 1 , wherein the aqueous solution of regenerant is passed downward at a space velocity of 1 to 5 hr −1 while the ultra-pure water is passed upward at a space velocity of 10 to 30 hr −1 .
3. The method as claimed in claim 2 , wherein, in the regeneration tower, parts brought into contact with the ion exchange resin, the regenerant and the ultra-pure water are composed of a fluororesin, a vinyl chloride resin or a polyolefin resin.
4. The method as claimed in claim 1 , wherein, in the regeneration tower, parts brought into contact with the ion exchange resin, the regenerant and the ultra-pure water are composed of a fluororesin, a vinyl chloride resin or a polyolefin resin.