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7683148 
Journal Article 
Impact, thermal, and shock sensitivity of molten TNT and of asphalt-contaminated molten TNT 
Mainiero, RJ; Miron, Y; Kwak, SSW; Kopera, LH; Wheeler, JQ; , 
1996 
INT SOC EXPLOSIVES ENGINEERS 
CLEVELAND 
1 
179-197 
English 
WOS:A1996BG72E00017 
The research reported here was part of an effort to evaluate the safety of a process to recover TNT from MK-9 depth bombs by the autoclave meltout process. In this process the depth bombs are heated to 121 degrees C so that the TNT will melt and run into a vat. Unfortunately, asphalt lining the inside surface of the bomb also melts and flows out with the TNT. Prior to this study, it was not known what effect the asphalt contamination and the higher than normal process temperatures (121 degrees C) would have on the sensitivity of the TNT.Testing was conducted on molten TNT and molten TNT contaminated with 2 pet asphalt at 90, 100, 110, 120, 125, and 130 degrees C. In the liquid drop test apparatus with a 2-kg weight, the molten TNT yielded a 50 pet probability of initiation at a drop height of 6.5 cm at 110 degrees C, decreasing to 4.5 cm at 130 degrees C. Asphalt-contaminated TNT was somewhat less impact-sensitive than pure TNT at temperatures of similar to 110 to 125 degrees C, but became more sensitive at 130 degrees C. There is a 50 pet probability of initiation at a drop height of 7.8 cm at 110 degrees C, decreasing to 3.3 cm at 130 degrees C. In the card gap test, the molten TNT detonated at high velocity for a gap of 0.25 inches at 90 to 125 degrees C and detonated at high velocity for a gap of 0.5 inches at 130 degrees C. For gaps of 0.5 to 3 inches at 90 to 125 degrees C and 0.75 inches to 3 inches at 130 degrees C, the TNT did not detonate at high velocity but produced a violent explosion that caused significant damage to the test fixture. For gaps of 4 inches the TNT did not react. In the gap test there was no significant difference between the pure and asphalt-contaminated TNT. The thermal analysis test results showed that when asphalt is present in TNT, it greatly accelerates the exothermic decomposition of TNT, starting at temperatures near 200 degrees C.The research demonstrated that asphalt-contamination of recovered TNT does not appear to have a significant effect on TNT shock sensitivity, but does adversely affect impact and thermal sensitivity. It appears that at relatively low shock stimulus levels, the molten TNT may be undergoing a low velocity detonation, wherein the shock wave traveling through the gap test pipe cavitates the molten TNT, greatly increasing its sensitivity. These results are crucial for assuring continued safety in recovering TNT from munitions through the autoclave meltout process. 
Anon 
22nd Annual Conference on Explosives and Blasting Technique 
ORLANDO, FL