Sulfur dioxide removal process with regeneration scale prevention

摘要

An oxidized magnesium sulfate-containing aqueous medium from a sulfur dioxide removal process using magnesium sulfite and magnesium bisulfite to remove sulfur dioxide from a gaseous stream is passed to a regeneration tank and an aqueous lime slurry fed thereto. The lime reacts with the magnesium sulfate to produce solid calcium sulfate and magnesium hydroxide, with the lime added in an amount sufficient to maintain the aqueous solution discharged from the regeneration tank at a pH of between 9.0-9.5, a magnesium ion content of about 200-600 ppm and a calcium ion content of about 2000-2500 ppm, so as to prevent scaling of lines and equipment downstream of the regeneration tank. <IMAGE>