Method for producing hydroxylammonium salts

A method for producing hydroxylammonium salts by reacting nitrogen monoxide (NO) with a molar hydrogen surplus in a reaction vessel in an aqueous medium of strong mineral acids in the presence of a noble metal catalyst suspended on a carbon-based support at excess pressure up to 10 bar and temperatures up to 80° C., the hydroxylammonium salt being constantly removed from the reaction vessel, said reaction vessel being a stirred reactor with an agitator shaft and agitator blades attached to the agitator shaft via a hub and bearing surface or support, characterized in that:

• a gas inlet and distribution system is provided in a lower part of the stirred reactor,
• a disk agitator is placed immediately above the gas inlet and distribution system,
• the disk agitator comprising the hub, said hub comprising the bearing surface or support with angled, concave and tilted agitator blades that rotate angled and concave sides in a direction of motion, and
• a two-blade blade agitator is provided on the agitator shaft in an upper part of the stirred reactor, individual leaves of the blade agitator being offset like lamellas at an angle of 0 to 30° C. to a blade axis so that they constantly wet a reactor cap when rotating.