Magnesium-enhanced sulfur dioxide scrubbing with gypsum formation

摘要

A wet scrubbing method for removal of sulfur dioxide from a gaseous stream uses a magnesium-enhanced lime scrubbing aqueous slurry, where a solids content in the aqueous slurry in a wet scrubbing unit is maintained at an amount of between 13 to 20 percent by weight. A bleed stream is removed from the aqueous scrubbing slurry at a pH of between 4.5-5.6 and fed to an oxidizing unit wherein calcium sulfite is oxidized to gypsum. The gypsum and residual solids in the discharge from the oxidizing unit are separated to produce a clarified solution, which is returned to the wet scrubbing unit.