PROCESS FOR THE RECOVERY OF SULFURIC ACID

摘要

A PROCESS FOR THE RECOVERY OF SULFURIC ACID In the recovery of sulfuric acid from waste sulfuric acid containing metal sulfates by concentration through evaporation and removal of the solid metal sulfates, the improvement which comprises concentrating the waste sulfuric acid by evaporation to a concentration of 26 to 32% by weight H2SO4 in an evaporation stage 1 and concentrating the acid obtained by evaporation in a steam-heated evaporation stage 2 to such an extent that the watersoluble metal sulfates are partly suspended in solid form in the acid concentrated by evaporation, the vapors from evaporation stage 2 being used as heating medium in an evaporation stage 3 in which the suspension from evaporation stage 2 is concentrated by evaporation to a concentration of 60 to 75% by weight H2SO4. As a result there is reduced consumption of steam and cooling water, reduced corrosion and shorter stoppages for cleaning. Le A 27 318