The expansion of Ammonium Nitrate (AN) is a novel technology. The guideline of this innovation is the self-sensitization of AN. It is a breakthrough form classic method. The approach to self-sensitization is the expansion of AN. Its essence is a surface active technology applied to powder industrial explosive, and it is a physical chemistry process under coercive crystallization.

In this paper, the mechanism and technical characteristics of expansion are discussed and its unique advantage is shown. The expanding technology of AN is mainly applied to rock expanded AN explosive and its comparison with other industry explosives is given. The expanding technology is also used in manufacturing of permitted explosive for coal mine.