NOVELTY - Potassium carbonate and ammonium sulfate are prepared by carbonizing potassium sulfate, ammonia and carbon dioxide; extracting and filtering reaction product via filter pump; introducing clarified filtrate into decompression distiller, distilling via grading and cooling in cooling tower; crushing ammonium sulfate crystal in first crusher and packaging to obtain ammonium sulfate product; and continuously evaporating and concentrating potassium carbonate trihydrate crystal in evaporation concentrator.    USE - Method is used for preparation of potassium carbonate and ammonium sulfate (claimed).    ADVANTAGE - The method converts waste material into useful product. The environmental pollution is reduced.    DETAILED DESCRIPTION - Potassium carbonate and ammonium sulfate are prepared by:    (A) dissolving industrial potassium sulfate into water for preparing potassium sulfate aqueous solution, introducing into carbonizing tower (1), where mass ratio of potassium sulfate, ammonia and carbon dioxide is 1:0.01-0.41:0.07-0.47 and introducing ammonia and carbon dioxide into carbonizing tower (1) for carbonizing;    (B) extracting and filtering reaction product via filter pump (2) for obtaining clarified filtrate and filter cake of black impurity;    (C) introducing clarified filtrate into decompression distiller (3) according to solidifying points of potassium carbonate and ammonium sulfate, distilling via grading and cooling in cooling tower (4) for obtaining potassium carbonate trihydrate crystal and ammonium sulfate crystal;    (D) crushing ammonium sulfate crystal in first crusher (5) and packaging to obtain ammonium sulfate product; and    (E) continuously evaporating and concentrating potassium carbonate trihydrate crystal in evaporation concentrator to obtain potassium carbonate, cooling potassium carbonate, crushing via second crusher, packaging for obtaining potassium carbonate product.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic diagram illustrating preparation of potassium carbonate and ammonium sulfate. (Drawing includes non-English language text).    Carbonizing tower (1)    Filter pump (2)    Decompression distiller (3)    Cooling tower (4)    First crusher (5)