Abstract: The process of converting FS smoke agent (a mixture of sulfur trioxide and hlorosulfonic acid) to sulfamic acid and ammonium chloride comprising the steps of dissolving the FS smoke agent in an organic solvent solution to obtain a solvation product, subjecting the solvation product to ammonia gas to obtain a sulfamic acid ammonium chloride mix, and separating and purifying the mix into sulfamic acid and ammonium chloride.

Abstract: Processes for the production of sulfamic acid by the reaction of urea, sulfuric anhydride, and sulfuric acid in (1) a two-stage process wherein the sulfuric anhydride used in the first stage at a temperature less than 50.degree. C. is dissolved in a halogenated fluorocarbon or a mixture of halogenated fluorocarbons having a boiling point of from 0.degree. to 50.degree. C. or (2) in a one-stage process at 60.degree. to 100.degree. C. with the sulfuric anhydride dissolved in a halogenated fluorocarbon or a mixture of halogenated fluorocarbons having a boiling point below 100.degree. C. at atmospheric pressure, the halogenated fluorocarbon serving to remove the heat generated by the exothermic formation of the sulfamic acid from the original reactants.

Abstract: When sulfur trioxide is reacted with ammonia, a melted reaction product containing mainly the ammonium salts of amidosulfonic acid and imido-disulfonic acid is obtained. According to the invention the melted reaction product is introduced into mineral acids. From the resulting solution, free amidosulfonic acid precipitates in high yield.