SODIUM NITRATE PRODUCTION PROCESS Russian patent published in 2003 - IPC

FIELD: inorganic compounds technology. SUBSTANCE: nitrite-nitrate solutions obtained by absorption of nitrogen oxides with soda or sodium hydroxide are concentrated by evaporation at 70- 90 C to summary salt concentration 750-900 g/l without solid phase separation and subjected to inversion. Inversion gases are diluted with air and returned into absorption stage, while contact separation of ammonia in order to form nitrose gases is started periodically as function of sodium nitrite consumption progress. Resulting sodium nitrate solutions are processed into salt solution by a method known by those skilled in the art, which includes crystallization and drying of product. EFFECT: enabled sodium nitrate production avoiding production of sodium nitrite and enabled utilization of nitric acid as nitrogen oxide source in inversion stage in place of catalytic ammonia oxidation. 2 cl, 1 dwg