Patent ID: 6992185

Claim:
A method for crystallizing epsilon polymorph 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.0 5,9 0 3,11 ]-dodecane (CL-20), comprising: preparing a substantially dry CL-20 solvent solution containing an amount of CL-20 dissolved in a CL-20 solvent; providing a crystallizer containing a CL-20 non-solvent; adding the substantially dry solvent solution to the crystallizer containing the CL-20 non-solvent to cause precipitation of epsilon polymorph CL-20 crystals by inverse precipitation technique; and separating the precipitated epsilon polymorph CL-20 crystals from the CL-20 non-solvent and the CL-20 solvent.