COMBINED METHOD OF PRODUCING SODIUM BICARBONATE AND MIXED TYPE NITROGEN FERTILIZER Russian patent published in 2019 - IPC C01C1/16 C01C1/24 C01D7/00 

FIELD: technological processes.

SUBSTANCE: invention relates to the technology of producing sodium bicarbonate and mixed nitrogen fertilizers by converting a solution of salts with ammonium carbonate or a mixture of ammonia and carbon dioxide and can be used in large-tonnage petrochemical units having a water treatment plant. Method is realized by conversion of an aqueous solution of inorganic salts in the presence of ammonia and carbon dioxide in the apparatus with a stirring device or in a counterflow column. Aqueous solution of inorganic salts used is a solution from ion-exchange water treatment filters enriched with sulphate and sodium chloride in molar ratio of (2–7):1, to which ammonia and carbon dioxide are added. After that, sodium hydrocarbonate is separated in form of a precipitate. Further, diluted sulfuric acid is added to the obtained aqueous composition based on sulphate and ammonium chloride until pH of solution is 6–6.2 for conversion into ammonium sulphate of unreacted ammonia and products of its reaction with carbonic acid to obtain nitrogen fertilizer.

EFFECT: technical result consists in development of optimum scheme of processing of solution of salts from ion-exchange filters of water treatment shops, enriched with chloride and sodium sulphate, into hydrocarbonate and ammonium derivatives.

1 cl, 2 ex