针对常用矿用阻化剂进行阻化实验,根据阻化效率、成本、溶解度等因素选出Na2CO3作为试验工作面的阻化剂,从隔绝氧气、吸热降温和负催化作用3个方面对Na2CO3阻化液的阻化机理进行分析。设计阻化液在试验工作面的制备工艺、钻孔布置和注液系统,使得每个注液孔有40 min的注液时间,从而避免了采煤与阻化作业相互影响;对预注阻化液前后试验工作面采空区内的气体体积分数和温度分布进行分析。研究结果表明:氧化区域位于采空区进风侧,在预注阻化液后,气体体积分数和温度分布明显降低;在预注阻化液后,煤的氧化进程推后11 d左右,从而降低了自燃危险性,有利于试验工作面采空区防灭火。
Na2CO3 was selected as the most suitable inhibitor of the test face from commonly used inhibitors in mining according to the inhibition efficiency of experiments, cost and solubility etc. Inhibition mechanism of Na2CO3 inhibition liquid was analyzed from three aspects, i.e. secluding oxygen, decalescence cooling and negative catalysis. Inhibition liquid preparation technology, drilling layout and liquid injection system of test face were designed. The gas volume fraction and temperature distribution in goaf before and after inhibition liquid pre-injection were analyzed. The results show that every liquid injection drilling has 40 min for liquid injection and the design so as to avoid the mutual influence between mining and inhibition operation. Oxidation zone is located in inlet side of goaf. Gas volume fraction and temperature distribution decrease significantly after inhibition liquid pre-injection. Oxidation process is delayed about 11 d after inhibition liquid pre-injection and the risk of spontaneous combustion is decreased. This is beneficial for fire prevention and extinguishment of test face in goaf.