Ammonium sulphate solutions are prepared by treating ammonium sulphite and sulphate solutions with a free oxygen-containing gas in the presence of a nitrogenous organic base heterogeneously dispersed in solution. Specified organic bases are pyridine, picolines, butidines, collidines, quinoline, bases containing condensed pyridic rings, e.g. dipyridyl, and pyridic bases obtainable by the destructive distillation of coal and in petroleum production as well as their derivatives. The reaction may be carried out between 40 DEG and 140 DEG C. In a typical example, air was blown through a solution containing ammonium sulphate and ammonium sulphite, with 2-methyl-5-ethyl pyridine dispersed therein, at 90 DEG C. The aqueous and organic phases were separated and ammonium sulphate recovered by crystallization. The mother liquor and the organic phase may be used for another oxidation.
展开▼
