Cast Porous Charges on a Base
of Ammonium NitrateľUrea Eutectic



Olga B. LITOVKA, Georgii D. KOZAK,
Ekaterina Ya. CHUGREEVA and Alexandr V. STARSHINOV

Mendeleev University of Chemical Technology,
Miusskaya Sq. 9,125190 Moscow, Russia

Abstract: 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 Tm<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 ? = 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 (? = 0.6-0.7 g/cm3) for charges
without confinement at initiation by means of booster or blasting cap.

Keywords: eutectic, ammonium nitrate, urea, fusion diagram, detonability,
detonation velocity

Full text: