| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for solidifying and recovering hydrofluoric acid from an aqueous solution absorbing hydrofluoric acid and hydrochloric acid from a hydrolyzed gas of fluorocarbon gas such as chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC) or hydrofluorocarbon (HFC). SOLUTION: The method of solidifying and recovering hydrofluoric acid is performed by introducing a hydrofluoric acid-hydrochloric acid aqueous solution from one side of a crystallization vessel to flow toward another side, adding CaCO<SB>3</SB>from another side into the aqueous solution to move toward the one side to form an excess state of hydrofluoric acid in one side and an excess state of calcium carbonate in another side to provide concentration gradient in the crystallization vessel and recovering CaF<SB>2</SB>in one side and CaCl<SB>2</SB>in another side. COPYRIGHT: (C)2004,JPO
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