Process for producing free hydroxylamine aqueous solution

Abstract

This invention provides a process for producing a free hydroxylamine aqueous solution, by letting an alkali react with separated sulfates, for conversion into ammonia and sulfates not containing any nitrogen atom, recovering the valuable ammonia and recycling it in the reaction system for effective use. This invention is a process for producing a free hydroxylamine aqueous solution, in which a free hydroxylamine aqueous solution is obtained by letting an aqueous solution or slurry containing hydroxylammonium sulfate and a gas mainly containing ammonia react with each other, mixing a solution mainly containing a lower alcohol with the produced aqueous solution or slurry, and separating the precipitated sulfates containing ammonium sulfate, comprising the steps of mixing an alkali with the separated sulfates, to produce ammonia gas, and recycling the ammonia in the reaction system.

Dependencies are inferred from the claim text.