Comparison of behaviour of 3 samples of nitrate based powders to classic black powder
Résumé
In this paper, we propose to study 3 products which are not considered explosives according to directive 1999/45/CE, which can be used in common applications such as agriculture or industry, which can be easily obtained and nevertheless, when blended and grinded in a particular way with a combustible can produce violent effects in particular circumstances. The 3 alkali-nitrate based powders studied are: a blend with industrial sodium nitrate, one with potassium nitrate fertilizer and one with calcium nitrate fertilizer. The behaviour of these 3 samples has been compared with classic black powder made with potassium nitrate. More precisely, the deflagration capability of these 4 powders has been studied. For that, several experimental tests have been performed, such as the Differential Thermal and Thermogravimetry Analysis (DTA/TG) test, the Audibert-Koenen test and the open air trough deflagration test. The results obtained allowed a ranking of these powders according to their reactivity, sensitiveness to confinement and deflagration velocity. The results show that the 3 studied powders are capable of violent behaviour according to the circumstances