PURPOSE: To prevent the discharge of harmful matter by treating a waste gas contg. gaseous chlorine trifluoride with an aq. mixed soln. of an alkali and a sulfite or bisulfite or the solid agent thereof or carrying out the treatment after the waste gas is washed with water.
CONSTITUTION: A waste gas contg. gaseous chlorine trifluoride is washed with an aq. mixed soln. of an alkali (sodium hydroxide is preferably used) and a sulfite or bisulfite (wet treatment). Alternatively, the waste gas is brought into contact with a solid neutralizer or a solid sulfite or bisulfite (dry treatment). Sodium fluoride low in solubility is deposited as a crystal when sodium hydroxide is used in the wet treatment, and solid silicon dioxide and the fluorides are deposited by the reaction of silicon tetrafluoride as the reaction product with the alkali in the dry treatment. Accordingly, the waste gas is previously washed with water to remove the precipitate forming components by the water, and then the treatment is carried out. A waste gas from cleaning is surely treated by such a method, and the discharge of harmful matter is prevented.
NAKANO HISAHARU
ICHIMARU HIROSHI
TAINAKA MASAHIRO
| JPS56147614A | 1981-11-16 | |||
| JPS61257223A | 1986-11-14 | |||
| JPS5219556A | 1977-02-14 |