摘要
在铝热管内静态爆破时,为实现电引火头点燃Al/Fe_(3)O_(4)铝热剂,并保证其自持燃烧长度,从而达到孔内全长嗣后加热静态破碎剂的目的,进行了电点火实验,该实验通过在封闭陶瓷管内的铝热自蔓燃体系中掺入不同质量分数的助熔剂,对比分析样品的热性能、产物物相组成和微观形貌,并通过灰岩单孔静爆试验验证了全长加热静态破碎剂的破碎增效作用。结果表明:添加助熔剂能够提升样品点燃可靠性与自持燃烧能力,且测得最佳添加量为2%,此时样品反应起始温度降低到901℃,自蔓燃长度为200 mm;助熔剂不会引起反应产物发生成分变化,但会使产物中α-Al_(2)O_(3)晶粒间界限逐渐模糊,晶粒排列更为紧密。在使用添加助熔剂的铝热管对灰岩钻孔内的静态破碎剂进行全长嗣后加热时,点燃后3~4 min即可观察到岩石裂隙的瞬时扩展和岩石破裂的现象,由此可见,添加助熔剂能够使铝热管稳定燃烧,同时对静态破碎剂进行增效,可大幅缩短爆破破岩时间。
In order to ignite the Al/Fe_(3)O_(4) thermite by detonator in the limited space and to ensure the self-propagating combustion length to heat SCDA,different mass fraction fluxes were introduced to the thermite self-propagating combustion system.The thermal properties,product phase compositions and microscopic morphology of the samples were comparatively analyzed.And the crushing effect of full-length heated SCDA was verified by limestone single-hole static crushing test.The results show that;(1)Adding a flux enhances the reliability of sample ignition and its ability of self-propagating combustion,and the optimal amount is 2%.at this point the initial reaction temperature of the sample drops to 901℃,and the length of self-propagating combustion is up to 200 mm.(2)The flux does not change the composition of the reaction product,but the boundaries betweenα-Al_(2)O_(3) grains are gradually blurred and the arrangement of the grains becomes more compact.(3)The SCDA was heated in the limestone hole after 4h by the Al/Fe_(3)O_(4) thermite tube with flux,and the instantaneous expansion rupture phenomenon of rock mass cracks was observed 3~4 min after ignition.It is confirmed that the addition of flux can stabilize the combustion of thermite and improve the efficiency of SCDA so that significantly shorten the time of rock breaking.
作者
戴传毅
蒋志明
桂羽彤
刘智
金跃凯
戴洲游
马洪杰
陈炎波
DAI Chuan-yi;JIANG Zhi-ming;GUI Yu-tong;LIU Zhi;JIN Yue-kai;DAI Zhou-you;MA Hong-jie;CHEN Yan-bo(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China;Hunan Shangshang Municipal Construction Investment Co.,Ltd.,Third Branch,Changsha 411610,China)
出处
《工程爆破》
CSCD
北大核心
2023年第6期133-141,共9页
Engineering Blasting
基金
国家自然科学基金资助项目(51508038)
湖南省研究生科研创新项目(QL20210188)。
