JPS54120292A - Bromine recovering method - Google Patents

Abstract

PURPOSE: To remove a trace amt. of NH₃ from an aq. soln. of a Br cpd. contg. NH₃ or NH₄ salt in recovery of Br₂ from the soln. with Cl₂ and steatm, by adding NaOH to the soln. to remove most of NH₃ as pretreatment and contacting the pretreated soln. to Cl₂, etc. while keeping the soln. at a specific pH value.

CONSTITUTION: An ap. soln. 1 of a Br cpd. contg. 50 g/l of NH₃ or NH₄ salt and NaOH 2 are introduced into regulation vessel 4, where they are heated to above 60°C with steam 3 at pH 11W13 to release most 5 of NH₃. Effluent 6 is fed to stripping tower 8 to strip NH₃-contg. gas 10 with stripping gas 9 such as air. Effluent 11 is then introduced into reaction vessel 13 and blown with Cl₂ gas 12 to remove a trace amt. of NH₃ while keeping effluent 11 at pH≥8. Effluent 15 is fed to acidification vessel 18 to add sulfuric acid 17 and introduced into reaction distilling column 20 for recovering Br₂, where it is treated with steam 21 and Cl₂ 22 to recover Br₂ 23.

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