R. Meyer J. Köhler A. Homburg Explosives

361 U-Zünder
Urea Nitrate
Harnstoffnitrat; nitrate d’urée
colorless crystals
empirical formula: CH5N3O4
molecular weight: 123.1
energy of formation: –1064 kcal/kg = – 4452 kJ/kg
enthalpy of formation: –1093 kcal/kg = – 4573 kJ/kg
oxygen balance: –6.5%
nitrogen content: 34.14%
volume of explosion gases: 910 l/kg
heat of explosion
(H2O liq.): 767 kcal/kg = 3211 kJ/kg
(H2O gas): 587 kcal/kg = 2455 kJ/kg
specific energy: 77 mt/kg = 755 kJ/kg
density: 1.59 g/cm 3
melting point: 140 °C = 284 °F (decomposition)
lead block test: 270 cm 3 /10 g
deflagration point: 186 °C = 367 °F
impact sensitivity: up to 49 N m no reaction
friction sensitivity: up to 353 N
no reaction
critical diameter of steel sleeve test:
at 1 mm P no destruction of steel sleeve
Urea nitrate is readily soluble in hot water and sparingly soluble in
ethanol. Its thermal stability is satisfactory. The compound is prepared
from urea and nitric acid. The salt is strongly acidic. Chemical stability
is poor.
U-Zünder
U-detonators are manufactured by ORICA Germany GmbH, Troisdorf,
for use in standard situations and where high safety against electrostatic
discharges is required. They are safe against 0.45 A and 8 mJ/
ohm. All-fire current is 1.5 A, all-fire energy 16 mJ/ohm. U-detonators
are available as instantaneous detonators and with 20 ms and 30 ms
short period delay, 18 delays each, and 24 delays of 250 ms long
period delay.
U-Zündmaschinen: the corresponding blasting machines are produced
by WASAGCHEMIE Sythen, Germany.