METHOD FOR PRODUCING HIGHLY CONCENTRATED AQUEOUS BORIC ACID SOLUTION

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a highly concentrated aqueous boric acid solution containing a diminished mineral acid even from raw water such as general waste water containing a very small amount of boron. SOLUTION: This method is for producing a highly concentrated aqueous boric acid solution in which an aqueous solution containing≥0.1 N at least one mineral acid selected from the group comprising sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid and 0.01-370 g/l boric acid is electrodialyzed; a production method in which an aqueous solution obtained by bringing boron-containing raw water into contact with a boron selective ion exchange resin and carrying out elution as boric acid from the resin with a mineral acid is used as the aqueous solution containing the mineral acid and boric acid; a production method in which the electrodialysis is carried out using batch-wise electrodialysis; a method for producing a highly concentrated aqueous boric acid solution having a low concentration of a mineral acid in which the resulting highly concentrated aqueous boric acid solution is brought into contact with an anion exchange resin; and a method for producing a highly concentrated mineral acid in which a mineral acid solution produced as a by-product by the said production method is further electrodialyzed. COPYRIGHT: (C)2003,JPO