TREATMENT OF ORGANIC HALOGEN COMPOUND WASTE GAS CONTAINING FLUORINE AND DEVICE THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a method for continuously treating an organic halogen compound waste decomposition waste gas containing fluorine with a small quantity of water and capable of recovering valuable CaF2 . SOLUTION: The method is by allowing HF and HCl in the decomposition waste gas continuously supplied from a decomposition device 20 of, for example, chlorofluorocarbon 12 to contact with an alkali solution continuously supplied from an alkali tank 40 and containing Ca(OH)2 in a prescribed concentration to form a neutralized material of insoluble CaF2 and soluble CaCl2 , circulating the alkali solution containing the neutralized material to return to the tank 40, taking out a fixed quantity of the alkali solution containing the neutralized material from the alkali tank 40 on the other hand to remove and recover CaF2 by a dehydrator 51, returning the separated water separated by the dehydrator 51 to the tank 40 after discharging a part thereof, supplying Ca(OH) 2 in the quantity corresponding to the quantity of the returned water by an alkali constant quantity feeder 44 and further supplying new water in the quantity corresponding to the discharged quantity of the separated water and Ca(OH)2 to the alkali tank 40 to regulate CaCl2 in the tank 40 to a prescribed concentration.