Military powdery nitroguanidine(NQ) manufactured by spray crystallization process often appears thick average grading,wide particle size distribution,and unsatisfied crystal regularity. And NQ with acicular crystal is not suitable for application in propellants. To improve the quality of military powdery NQ,crystallization properties,principle of crystal transformation and crystallization process conditions of NQ were analyzed and studied. Vacuum crystallization was used to replace spray crystallization in ...