SU11018A1 - The method of producing ammonium sulphate - Google Patents

Description

The authors noted that when ammonium sulphate is obtained by the exchange decomposition of calcium sulfate (gypsum) with ammonia and carbon dioxide, it is advantageous to work with an excess of ammonia compared to carbon dioxide, since the reaction proceeds, especially smoothly. As a consequence, according to the proposed method, the reaction is carried out by introducing an excess of ammonia from the very beginning, and it is possible to add all the amount of ammonia at once.

Getting ammonium sulfate on the proposed method can be performed, for example, as follows. The ground gypsum is mixed with a mixer in the boiler with the wash water remaining from the previous process. Ammonia is introduced into the liquid gypsum dough. At the beginning of the process, cooling is applied and only towards the end does the temperature rise to about 50 °. As soon as the liquid contains enough ammonia, for example, 2-, gases containing carbon dioxide are introduced into it and the temperature is maintained at about 60 °. Carbon dioxide is injected until the reaction ceases. With proper calculation of the initial amount of ammonia, by the end of the reaction, the solution contains about 0.3 to 0 more ammonia. Ammonia and carbon dioxide can be introduced alternately or simultaneously. The waste gases from the boiler continuously flow into the second boiler with the same load. To prevent ammonia losses, the temperature in the boiler is not raised above 45. The second boiler goes into operation instead of the finished first boiler, etc. The insignificant amount of ammonia remaining at the end of the reaction is distilled off separately or left in solution. In the latter case, the amount of sulfuric acid needed to neutralize the ammonia is added to the filtered ammonium ammonium sulphate solution before evaporation. The subject of the patent. 1. A method of producing ammonium sulfate from calcium sulfate by reaction with ammonia and carbon dioxide, characterized in that the reaction is all the time carried out with an excess of ammonia, 2. Acceptance of the method outlined in paragraph 1, characterized in that from the very beginning the whole amount is added ammonia-as necessary for the reaction, and its excess ,.