REMOVING METHOD FOR HYDROGEN CYANIDE

摘要

PURPOSE:To remove efficiently hydrogen cyanide incorporated in a gas to be treated by bringing the gas contg. hydrogen cyanide into contact with a specified absorption liquid. CONSTITUTION:An absorption liquid 5 is obtained by adding a pH regulator to an aq. soln. contg. 0.01-0.1wt% cationic nitrogen-contg. high molecular compd. (e.g. melamine formaldehyde polycondensation product) having a gorup shown in the formulas = NR and -NR2 (R is H, OH group, oxymethyl, alkyl and carboxyl.) to control pH to 6-9. Then this absorption liquid 5 is circulated to a plate-type gas absorption tower 1 via a circulation pump 3 and also a gas 10 contg. hydrogen cyanide is fed from the under part of the absorption tower 1 and countercurrently brought into contact with the absorption liquid to absorb and remove hydrogen cyanide and thereafter the gas 14 is discharged from the top of the tower and the absorption waste liquid 12 is discharged from the bottom of the tower.