The Impact of pH Value on the Performance of a Novel Ammonium Nitrate-Based Explosive

To enhance the intrinsic safety and reduce the energy consumption of industrial explosive production, hexamethylenetetramine (HMTA), a water-soluble compound, has replaced the traditionally used insoluble fuel oil in ammonium nitrate-based (AN-based) explosives. The oxidizer (AN) and the fuel (HMTA) were combined in water to create an intermolecular explosive, termed “ammonium amine explosive”. The influence of pH levels ranging from 4.0 to 5.8 on the density, cross-linking time, microbubble formation, detonation velocity, and water resistance was investigated using density measurements, a digital viscometer, an optical microscope, a detonation velocity tests, and a conductivity meter. The results indicate that ammonium amine explosives prepared at varying pH levels generate numerous chemically sensitized microbubbles, which have a decreasing mean diameter as the pH decreases. Lower pH values are associated with faster foaming rates and shorter cross-linking and foaming times. The detonation velocity of ammonium amine explosives ranges from 3500 and 4200 m/s, which is slightly lower than that of conventional emulsion explosives. Furthermore, the water resistance of ammonium amine explosives was compared for cross-linking times of 1 and 24 h, yielding contrasting results. A pH value of approximately 5.2 delineates the boundary between in situ mixing and packaged explosives for ammonium amine explosives, with packaged explosives exhibiting greater advantages at pH values above 5.2, and in situ mixing being more advantageous at lower pH values. These findings provide theoretical support for enhancing the performance of this novel water-resistant nitro explosive and facilitate its potential industrial application.