Process for preparing N,N-diacetic acid aminomethylenephosphonic acid

摘要

An energy saving process for preparing N,N-diacetic acid aminomethylenephosphonic acid by reacting an alkali metal salt of iminodiacetic acid in aqueous strong mineral acid solution with phosphorous acid and formaldehyde and then adding sufficient water to dissolve the alkali metal salt formed during the reaction. The desired product is recovered as a precipitate from the solution.