Method for separating fluorine from fluorine-containing wastewater

摘要

PROBLEM TO BE SOLVED: To provide a method which enables fluorine to be easily and efficiently separated and removed at a low cost, from fluorine-containing wastewater generated from a nonferrous metal smelting process, and moreover enables fluorine to be always stably and surely separated and removed without limiting the kind of a neutralizer used when obtaining the fluorine-containing wastewater.SOLUTION: A method for separating fluorine from fluorine-containing wastewater is provided in which fluorine in the fluorine-containing wastewater is separated and removed by precipitating fluorine as calcium fluoride, the fluorine-containing wastewater being generated from a nonferrous metal smelting process and containing magnesium sulfate, the method comprising: a sulfate ion concentration adjustment step S11 in which a sulfate ion concentration in the fluorine-containing wastewater is adjusted; and a fluorine precipitation and removal step S13 in which fluorine in the fluorine-containing wastewater is separated and removed as precipitates. In the sulfate ion concentration adjustment step S11, a sulfate ion remover is added into the fluorine-containing wastewater to adjust the sulfate ion concentration in the fluorine-containing waste water to 1.5 g/L or less.SELECTED DRAWING: Figure 1