| 摘要 |
PROBLEM TO BE SOLVED: To provide an economical method for recovering hydrofluoric acid from a fluorine-containing waste water with improved efficiency through a simple and easy process. SOLUTION: This method for recovering hydrofluoric acid from the fluorine-containing waste water comprises adding, to the waste water, calcium hydroxide alone or a mixture of calcium hydroxide and calcium phosphate obtained by adding a phosphoric acid raw material to calcium hydroxide, applying a carbon dioxide treatment to convert a fluorine ion into a calcium fluoride-containing reaction product, and treating the reaction product with an inorganic acid to convert the treated product into hydrofluoric acid. COPYRIGHT: (C)2004,JPO
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