US EPA

8398859 

Journal Article 

Reaction rates of ammonium nitrate in detonation 

Cook, MA; Mayfield, EB; Partridge, WS 

1955 

1 

Journal of Physical Chemistry
ISSN: 0022-3654 

59 

8 

675-680 

English 

10.1021/j150530a002 

Detonation velocity and wave shape were measured as a function of charge diameter over wide diameter ranges in the explosives (1) cast 70.7/29.3 composition B-ammonium nitrate (AN), (2) cast 50/50 amatol (TNT-AN), (3) a loose-packed mechanical mixture of 50/50 TNT-AN, and (4) pure AN. The velocity-diameter curves were interpreted by the existing theories ("nozzle," "curved front") of reaction rates in detonation. Comparisons of the computed reaction rates of AN in low and high density 50/50 TNT-AN showed that the specific rate constant was two to three times as great at a density ρ1, of 1.53 g./cc. as at ρ1 = 1.0 g./cc. This seems to show that the detonation temperature is about 300 to 600° higher at ρ1 = 1.53 than at ρ1 = 1.0 which bears out the approximate validity of the covolume α(v) equation of state for this explosive. Wave shape measurements showed consistently spherical wave fronts of steady state radius of curvature/diameter (Rm/d) ratios between 0.5 and 3.8 depending on the explosive and its diameter and density. The Rm/d ratio in pure AN was near unity in all cases and showed no definite diameter dependence. In loose-packed 50/50 TNT-AN, Rm/d was 0.51 at the critical diameter and 2.1 at the maximum diameter studied (25 cm.). In 50/50 cast amatol Rm/d increased from below unity near the critical diameter to 2.3 (still increasing) at the maximum diameter studied (20 cm.) and in cast composition B-AN, Rm/d increased from below unity at the critical diameter to a maximum value of 3.8 which maintained for all diameters greater than 3.8 cm.