Research On The Safety Of Ammonium Nitrate Emulsion And Influence Mechanism Analysis

In this dissertation,some experimental studies have been carried out focusing on several problems lack of concern on the safety of ammonium nitrate emulsion(ANE),such as the thermal decomposition characteristics with large scale of ANE,the influence of environmental stimulus on the demulsification of vehicle-mounted emulsion and the thermal stability of ANE with unexpected interfusion of chemical sensitizer.For the lack of concern about the thermal decomposition characteristics with large scale of ANE,different experimental methods with different testing mass were employed.The results show that the onset temperature of ammonium nitrate(AN)is lower than that of ANE in the non-adiabatic Differential Scanning Calorimetry(DSC)test with small test dose.In the adiabatic Accelerating Rate Calorimeter(ARC),the former is larger than the latter,which is regarded to be caused by the different testing mechanism,small test mass and the thermal decomposition characteristics of AN,etc.While in the Modified Vented Pipe Tests(MVPT)with much larger test dose,the onset temperature of AN and ANE are much lower.Conclusions by the comparison of DSC,ARC and MVPT could be obtained that thermal decomposition will carry out much easier for large-scale samples.Scale effect is obviously exited between the sample dose and thermal stability,and heat dissipation is more difficult to occur for AN than ANE in large-scale storage.To study the influence of environmental stimulus on the demulsification of vehicle-mounted emulsion,the high-low-temperature cycling test and vibration test were applied to simulate environmental stimulus,for the accelerated aging treatment of emulsion samples.The influence rules of environmental stimulus on the appearance,ammonium nitrate precipitation quantity,electric conductivity,viscosity of the emulsion sample lixiviums were obtained.Results show that the temperature shock appears comparatively obvious effect on the demulsification of emulsion samples,and the vibration shock appears less effect,however the temperature-vibration coupled aging shows a much more remarkable effect.The DSC,large-scale heating program test and simplified vented pipe test were applied to the thermal stability measurement.Results show that the thermal stability is lowered with the increase of the temperature shock aging period and the test dose.ANE Gap test and Konen test were also carried out on the vehicle-mounted emulsion after temperature shock aging.Results show that the sensitivity to shock wave and the sensitiveness to the effect of intense heat under high confinement are both increased with the increase of the temperature shock aging period.The DSC,ARC,large-scale heating program test and Dewar test were employed to study the thermal stability of ANE with unexpected interfusion of crystalloid sodium nitrite(NaNO2).The influence of crystalloid NaNO2 on the thermal stability of AN,ANE is obtained.Both the non-adiabatic DSC test and the adiabatic ARC test results show that crystalloid NaNO2 can obviously accelerate the thermal decomposition of AN and ANE,and lowered the thermal stability of mixed sample systems.The results of large-scale heating program test show that with the increase of NaNO2 adding amount,the onset temperature decreases,the top reaction temperature rises,and the reaction time is advanced.The result of the Dewar test shows that the sample of AN-2.50%NaNO2 is thermally stable at ?40?,and unstable at?45?,while the sample of ANE-2.50%NaNO2 is thermally stable at ?100 ?.And the samples are thermally stable when the adding amount ratios of NaNO2 for AN are ? 2.50%(40?)or 0.25%(45?),and for ANE is?2.50%(100?).