【作者】 吴红波；

【导师】 颜事龙；

【作者基本信息】 安徽理工大学 ， 安全技术及工程， 2011， 博士

【摘要】 在微差爆破作业过程中,乳化炸药常常会发生压力减敏现象,表现为爆轰性能下降,半爆或拒爆现象,尤其是在炮孔间距较小、水下爆破和矿井有淋水工作面时,这种现象就更加显著。乳化炸药发生减敏会使后续爆破和施工更加困难,使工期延误,影响施工进度,尤其是发生拒爆时,在盲炮的处理上技术比较复杂,危险性大,容易造成人身伤亡事故。因此,研究乳化炸药的减敏机理,减少和避免减敏现象的发生,对于保证正常爆破工程作业,促进乳化炸药的推广和应用具有重要的意义。本文利用水下爆炸测试系统,设计了乳化炸药在动态压力作用下的受压减敏方法,测试了敏化剂的含量和种类、乳化剂含量和种类对乳化炸药减敏程度的影响,利用水溶法测量了乳化炸药在动压作用后析晶量的变化,利用电导法测量了乳化炸药受压前后电导率的变化,用显微镜对乳化炸药在受压前后微观结构的变化进行了观测,并用激光粒度分析仪分析敏化剂玻璃微球在受压前后粒径的大小。研究结果表明,敏化剂的种类和含量对乳化炸药的减敏程度有重要的影响,玻璃微球敏化的乳化炸药的抗动压性能要优于膨胀珍珠岩敏化的乳化炸药,在保证乳化炸药正常爆轰的情况下,适当降低乳化炸药中敏化剂的含量,可以使乳化炸药的析晶量减少,抗动压性能增加,适当提高乳化剂的含量可以提高乳化炸药的抗动压性能,不同乳化剂乳化的乳化炸药,其抗动压性能不同等。本文在实验的基础上对乳化炸药在动压作用下的减敏机理进行了分析和探讨,认为乳化炸药在动压作用后,敏化气泡载体的破坏和微观结构的变化是造成乳化炸药减敏的主要原因,有效气泡数量的减少及气泡破裂后对乳化炸药界面膜的破坏使乳化炸药爆炸性能降低,微观结构破坏主要表现在乳胶颗粒发生聚集,破乳和析晶,乳胶颗粒的粒径变大,从而使乳化炸药爆轰性能下降,发生减敏现象。更多还原

【Abstract】 Pressure desensitization of emulsion explosives often occur during the millisecond blasting, which behaves as detonation performance decreasing, half explosion or misfire, especially, the phenomenon is more significant with the blast hole span small relatively, underwater blasting and the water trickling working face of mine shaft. It will make subsequent blasting and construction more difficult, make construction period delay, and effect the progress after the desensitization occurs of emulsion explosive, especially, when the misfire occurs, the dealing means is relatively complex in the misfired charge treatment and casualty accidents easily happen. So it is very important to research on the desensitization mechanism of emulsion explosive in order to decrease or avoid the desensitization, ensure normal blasting operation and promote the popularization and application of emulsion explosive.Using underwater explosion test system in this paper, the experimental method was designed to research on the desensitization of emulsion explosive under dynamic pressure. The content and type about sensitization agent and emulsifier were measured; the effects on the desensitization degree of emulsion explosive were discussed. The crystallization quantity of emulsion explosive was measured by water dissolution under dynamic fore-and-aft. And the variation of electrical conductivity was also measured by conductivity method. Microstructure was observed by microscope after emulsion explosive was pressed or not, and the particle size of GMB (glass micro-balloon) was tested by laser particle analyzer. The results of research show that the type and content of sensitization agent have an important effect on desensitization degree of emulsion explosive, the performance of dynamic pressure resistance of GMB is better than that of expanded perlite. So if the sensitization agent content decreases appropriately in the case of ensuring emulsion explosive detonation normally. It can make crystallization quantity of emulsion explosive decrease and make the performance of dynamic pressure resistance increase. The performance of dynamic pressure resistance can be improved if the emulsifier content increases and the performance of pressure resistance will be difference if the type of emulsifier is difference, etc. The desensitization mechanism of emulsion explosive was analyzed and discussed under dynamic pressure based on the experiment in this paper. It is believed that the main reasons on desensitization of emulsion explosive are the destruction of sensitization bubble carriers and variation of microstructure under dynamic pressure. It makes detonation performance decrease that effective bubbles decrease and destruction of interfacial film which caused by bubble carrier breakdown. Destructions of microstructure show that colloidal particles occurs aggregation, demulsification, crystallization, and colloidal particle sizes increase, it makes detonation performance of emulsion explosive decrease, and occur desensitization.更多还原