METHOD OF PROCESSING SULFITE-BISULFITE SOLUTIONS Russian patent published in 2001 - IPC

FIELD: processing of sulfite-bisulfite solutions, more particularly purification of gases from sulfur dioxide. SUBSTANCE: method comprises treating solution with sulfate agent to prepare ammonium and alkali sulfates, crystallizing and drying final product in which sulfite-bisulfite solution is mixed with calcium sulfate in the presence of ammonia or other alkaline reagent at SO₃ to CaSO₄ molar ratio of 1:1-1.5, temperature of 20-60 C and pH of 6.0-7.5 and filtered, and calcium sulfate is natural gypsum, phosphogypsum or phosphosemihydrate. EFFECT: simplified process, elimination of consumption of sulfuric acid and heating steam. 3 ex