USED ETCHING GAS TREATING METHOD AND USED ETCHING GAS TREATMENT APPARATUS

摘要

PROBLEM TO BE SOLVED: To greatly reduce an amount of drain by recycling water generated when treating used etching gas.

SOLUTION: This treatment apparatus 100 is provided with: a detoxifying facility 74 for burning used etching gas discharged from an etching apparatus 72; a scrubber 53 for producing hydrogen fluoride by bringing water into contact with gas discharged from the detoxifying facility 74 and causing a reaction; a reactor 20 for reacting hydrogen fluoride generated in the scrubber 53 with a calcium compound to form a calcium fluoride-containing treating solution 22; a treatment tank 30 for separating solid from liquid by membrane filtration of the calcium fluoride-containing treating solution 22 from the forming tank 20; a filter press 36 for recovering calcium fluoride precipitated in the treatment tank 30; a regeneration tank 40 forming hydrogen fluoride by adding an acid to the calcium fluoride recovered in the filter press 36 and causing a reaction; and a water recycling line for returning filtrate filtered in the treatment tank 30 to the scrubber 53.

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