Preparation method of sphericized hexanitrohexaazaisowurtzitane (HNIW) crystal

The invention provides a sphericized epsilon type hexanitrohexaazaisowurtzitane (HNIW) crystal and a preparation method thereof. The preparation method of the sphericized epsilon type hexanitrohexaazaisowurtzitane (HNIW) crystal comprises the following steps: a) dissolving alpha-HNIW, beta-HNIW and gamma-HNIW or mixture of the alpha-HNIW, the beta-HNIW and the gamma-HNIW into a solvent to form a saturated solution of the alpha-HNIW, the beta-HNIW and the gamma-HNIW or the mixture of the alpha-HNIW, the beta-HNIW and the gamma-HNIW; b) adding a crystal growth control agent to the saturated solution and adding an anti-solvent to form a supersaturated solution; and c) adding epsilon-HNIW seed crystals to the supersaturated solution and continuously adding the anti-solvent until all HNIW in the supersaturated solution is released to grow a sphericized epsilon-HNIW crystal. The sphericized epsilon-HNIW crystal does not have sharp edges and corners but has a multi-faceted spherical shape, particle size of 20 to 500 um, chemical purity of 98 to 99.9 percent determined by high performance liquid chromatography, porosity of 0.01 percent to 0.40 percent and 5Kg drop hammer impact sensitivity H50 of 26 to 52 centimeters.