Crystallization of spherical ammonium dinitramide (ADN) particles

The described process aims to produce spherical ammonium dinitramide (ADN) particles of different sizes with a narrow particle size distribution. The crystallization process presented in this paper consists of two stages. In the first stage, molten ADN is dispersed in a continuous phase in which ADN is insoluble. The droplet size produced can be controlled by varying the a mount of mechanical energy supplied to the two-phase system. In addition to discussing the influence of the different process parameters, such as disp ersion rate, dispersion power, emulsification time etc. this paper also rep orts the influence of emulsifying agents and the rheological behavior of th e continuous phase. In the second stage of the process, crystallization of the emulsified ADN droplets to spherical, solid particles is obtained by re ducing the temperature of the system. The process described enables product ion of spherical ammonium dinitramide particles with mean sizes from 10 mu m to 600 mu m. The product quality of the crystallized ADN, which is also d iscussed in this paper, was determined using various analysis techniques, i ncluding differential scanning calorimetry (DSC), IR spectroscopy, ion chro matography and laser light diffraction spectrometry.