The Chemical Behavior of Low Valence Sulfur Compounds. III. Production of Ammonium Sulfamate by the Oxidation of Ammonium Thiosulfate

The oxidation of ammonium thiosulfate with compressed oxygen in aqueous ammonia solution was examined. It was found that ammonium sulfamate and ammonium sulfate are mainly produced and a small amount of nitrite and imidodisulfonate obtained in the final solution. The most suitable conditions to produce ammonium sulfamate from ammonium thiosulfate industrially are as follows: reaction temperature 100°C, oxygen pressure 50 kg/cm2, concentration of ammonia 16 mol/l, concentration of cupric ion 0.1–0.2 mol/l. The electrolytic oxidation, hydrogen peroxide oxidation and ozone oxidation of ammonium thiosulfate were also examined.