METHOD OF PREPARING DINITRAMIDIC ACID AND SALTS THEREOF

摘要

The invention relates to a method of preparing dinitramidic acid HN(NO2)2 and salts thereof having the formula M?+n(-N(NO¿2)2)n, wherein M is a metal cation or a nitrogen-containing cation and n = 1-3. The dinitramide salt can be used as oxidiser in solid propellants. Dinitramidic acid is prepared by nitration of a compound selected from a group consisting of NH2NO2, NH4NH2CO2; NH2SO3H, NH(SO3H)2, N(SO3H)3, and its salts with metal cations or organic cations, e.g. NH(SO3NH4)2, and other products formed when ammonia is reacted with sulphuric trioxide, with a common nitrating acid such as nitric acid/sulphuric acid or nitric acid/acetic anhydride. The invention also relates to a method of preparing dinitramide salt, comprising neutralisation of dinitramidic acid with a neutralising agent, e.g. ammonia, and recovery of the dinitramide salt from a mixture of salts formed in the neutralisation. An aqueous solution of the salt mixture is passed through a column containing an adsorbing agent which adsorbs the dinitramide salt and is selected from a class consisting of activated carbon, silica gel and zeolites. The dinitramide salt is eluted with an elution agent consisting of hot water and/or a polar organic solvent, e.g. acetone, acetonitrile, 2-propanol and other lower alcohols and mixtures thereof.