TREATMENT PROCESS FOR WASTEWATER CONTAINING FLUORINE

摘要

PROBLEM TO BE SOLVED: To provide a fluorine-containing wastewater treatment process which enables selective separation/recovery of fluorine in raw wastewater which contains heavy metals and fluorine and is discharged from a copper smelting process or the like, prevention of fluorine accumulation in the copper smelting process due to the repeated smelting treatment of precipitated solid matter that is separated and recovered from the wastewater and returned to the copper smelting process, from being caused and also, reduction in wastewater treatment cost.;SOLUTION: This treatment process comprises adding a slurry of an neutralizing agent such as slaked lime to raw wastewater in a first reaction vessel 1 so that the pH value of the wastewater is adjusted to 5-6, concentrating the resulting slurry containing the neutralization product thus formed, in a thickener 4 to obtain a concentrated slurry having a 180-250 g/l slurry concentration, withdrawing the concentrated slurry from the thickener 4, agitating and mixing the concentrated slurry and the above neutralizing agent slurry together, to obtain a mixed slurry and to return the mixed slurry to the first reaction vessel 1, and also, recovering sludge having a high fluorine content from the bottom of the thickener 4 and obtaining treated wastewater discharged from the top of the thickener 4.;COPYRIGHT: (C)2001,JPO