Abstract: A process is provided for recovering sodium bicarbonate and ammonium sulfate from a solution containing sodium sulfate derived from a process for removing sulfur contaminants out of a gas with sodium bicarbonate reagent. Sodium bicarbonate is precipitated and removed from the solution. Sodium sulfate or ammonium bicarbonate is added to the solution to form a second precipitate of sodium bicarbonate, which is removed from the solution. The solution is conditioned by either heating the solution to 95.degree. C. to liberate ammonia and carbon dioxide or by adding sulfuric acid to the solution to decompose any carbonates. The solution is cooled to a temperature between -2 to 2.degree. C. to form a third precipitate of sodium bicarbonate. Sulfuric acid is added to the solution to decompose any carbonate minerals, and purified ammonium sulfate solution is recovered.

Abstract: A process for producing sodium bicarbonate and sodium carbonate. The process includes reacting within a reactor sodium sulfate in aqueous solution with ammonia and carbon dioxide to precipitate sodium bicarbonate and form a first mother liquor. The sodium bicarbonate is separated and dried to produce sodium bicarbonate product. Alternatively, the sodium bicarbonate may be calcined to convert it to sodium carbonate. The first mother liquor may be evaporated to precipitate unreacted sodium sulfate, with the formation of a second mother liquor. The second mother liquor may be cooled to precipitate a double salt of sodium sulfate/ammonium sulfate and water. A third mother liquor is formed from this process. The latter-mentioned liquor from the precipitation of the double salt is evaporated to precipitate a substantial pure ammonium sulfate in a purity of greater than approximately 75 wt %. A fourth mother liquor is formed.