Exploratory Development on a New Process to Produce Improved RDX (Cyclotrimethylenetrinitramine) Crystals: Supercritical Fluid Anti-Solvent Recrystallization

摘要

Topic A86-142 of the FY 1986 DOD SBIR Solicitation sought investigation of methods which could produce improved intragranular cavity free RDX (cyclotrimethylenetrinitramine) crystals of 100-150 microns size. RDX produced by the current method, recrystallization from cyclohexanone-water solution by evaporative concentration, contains intragranular cavities; they can interfere with the performance of the explosive. Phasex Corporation proposed the use of supercritical fluids as anti-solvents to recrystallize RDX from organic solvent solutions. The concept is based upon the phenomenon of absorption of gas near its critical point by an organic solvent. The absorption of the gas lowers the dissolving power of the organic solvent for RDX resulting in nucleation of RDX. It was suggested that process parameters such as RDX concentration, organic solvent, gas pressure and temperature, rate of introduction of gas and similar factors could be controlled to form the desired particles. Keywords: Explosives, RDX, HMX, Recrystallization, Supercritical fluids, Fine particles. (MJM)