METHOD FOR REMOVING FLUORINE FROM WASTE GAS

摘要

PROBLEM TO BE SOLVED: To provide a new method for removing fluorine in waste gas discharged from a semiconductor production facility. SOLUTION: Fluorine is removed from the waste gas 16 generated in cleaning, etching, or CVD work in the production of semiconductors by keeping the concentration of fluorine in the waste gas supplied to the fixed beds 18 and 19 of activated alumina of high porosity to be 4 vol.% or below while the waste gas is passed through the fixed beds 18 and 19. Nitrogen can be added to the waste gas in order to control the concentration of fluorine. By controlling the concentration of fluorine in the waste gas by using alumina the initial porosity of which is higher than 0.35 cm3/g, the fixed beds 18 and 19 can be operated without blockage and sintering.