Cast Porous Charges on a Base of Ammonium Nitrate-Urea Eutectic

There are great number tasks of explosive technique, requiring the charges with low pressure and detonation velocity. Powerful tool of regulation of these parameters is lowering of charge density. The main goal of this work is elaboration of technology of manufacture and investigation of explosive properties of charges on a base of eutectic ammonium nitrate-urea mixtures (AN/UR) that have melting point T[m] < 100 C. The physicochemical properties of these mixtures were investigated by means of DSC method and fusion diagram of them was plotted. The composition AN/UR 80/20, that has Tm= 80-90 C was chosen for subsequent investigation. The molten composition was mixed with fine aluminum powder, portion of it was placed into paper tube. The level of a liquid was less than length of the tube. Crystallization of melted mixtures was carried out in vacuum chamber, the level of liquid increased at pumping because of expansion of air bubbles introduced with aluminum particles and reached the upper cork of tube. In such a way porous charges were formed. The dependence of charge density vs. population of tubes by melted mixtures was plotted. Calculated heat explosion of mixtures at content of aluminum Al = 10-15% is Qv = 4.5-5.3 MJ/kg, calculated detonation velocity at density ρ = 0.5-1 g/cm3 changes from D = 3.2 to 5.2 km/s. Detonability of charges was investigated experimentally. Failure diameter (df) of detonation was measured, it was df = 22 mm (ρ = 0.6-0.7 g/cm3) for charges without confinement at initiation by means of booster or blasting cap