| 摘要 |
PROBLEM TO BE SOLVED: To provide a recovering method of fluorine by which calcium fluoride having excellent filterability in membrane treatment and a comparatively large particle diameter can be produced. SOLUTION: Fluorine-dissolved aqueous solution is blended with calcium carbonate and /or calcium sulfate to produce calcium fluoride and thereby fluorine is recovered. By suitably choosing particle size of calcium carbonate and calcium sulfate in used, calcium fluoride of desired particle size can be produced. Thus, a calcium fluoride having a comparatively large particle diameter and excellent filterability can be produced and membrane treatment can be effectively performed to reduce concentration of fluorine contained in waste water or the like. COPYRIGHT: (C)2004,JPO
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