摘要
在深部开采阶段,随地应力增大煤层透气性降低。煤层酸化技术通过溶解或溶蚀孔裂隙中的填充物以提高透气性,而水锁效应限制了该技术的发展,气润湿反转剂的加入可以有效减轻酸化后的水锁效应。为了探讨酸化时加入气润湿反转剂对煤吸附特性的影响,以山西TL煤为研究对象,制备了原煤、蒸馏水浸泡煤、酸液浸泡煤和酸液+气润湿反转剂浸泡煤,干燥处理后分别进行了甲烷等温吸附实验、XRD实验和高压压汞实验。甲烷等温吸附实验结果表明,酸液+气润湿反转剂浸泡煤的吸附常数a值大于原煤和蒸馏水浸泡煤,但小于酸液浸泡煤,说明水分浸润降低了煤对甲烷的吸附能力,而酸化促进了吸附性能的提升,气润湿反转剂的加入又降低了煤对甲烷的吸附能力;XRD实验表明经酸液浸泡后的煤样中绿泥石矿物消失不见,高岭石、伊利石和钙长石的成分明显减少,酸液+气润湿反转剂浸泡煤的石英含量明显减少;高压压汞测试结果显示蒸馏水浸泡煤、酸液浸泡煤和酸液+气润湿反转剂浸泡煤的孔容均大于原煤,且酸液+气润湿反转剂浸泡煤小于蒸馏水浸泡煤和酸液浸泡煤。通过对实验结果的理论分析厘清了酸化-气润湿反转对煤体吸附特性的影响机制,气润湿反转剂的加入降低了煤对的甲烷吸附性能,促进酸化反应并产生新物质,而且在水楔作用和干燥升温作用下改变了煤的孔隙特性。在煤层酸化实践中,应及时进行清洗,避免失水后反应物重新固化,堵塞孔隙。
In the deep mining stage of coal mine,the permeability of coal seam decreases with the increase of in-situ stress.Coal seam acidification technology improves the permeability by dissolving the fillers in pores and fissures,but water blocking effect limits the development of this technology,and the addition of gas wetting reversal agent can effectively reduce the water blocking effect after acidification.In order to explore the effect of adding wetting reversal agent on the adsorption characteristics of coal during acidification,raw coal(RC),distilled water impregnated coal(DWC),acid liquid immersed coal(ALC)and acid liquid-gas wetting reversal agent impregnated coal(ARC)were prepared,and methane isothermal adsorption experiment,XRD experiment and high-pressure mercury pressure experiment were carried out after drying treatment,respectively.The results of methane isothermal adsorption experiments show that the adsorption constant a of ARC is greater than that of RC and DWC,but less than that of ALC,indicating that water infiltration reduced the adsorption capacity of coal for methane,while acidification promoted the improvement of adsorption performance,and the addition of gas wetting reversal agent reduced the adsorption capacity of coal for methane.XRD results showed that the chlorite minerals disappeared and the components of kaolinite,illite and alastite were significantly reduced in ALC and ARC;The quartz content of ARC was significantly reduced.The results of high-pressure mercury pressure showed that the pore capacity of RC,ALC and ARC were greater than that of DC,and that of ARC was smaller than that of DWC and ALC.Through the theoretical analysis of the experimental results,the influence mechanism of acidification-gas wettability alteration on the adsorption characteristics of coal was clarified.the addition of gas wetting reversal agent reduced the methane adsorption performance of coal,and promoted acidification reaction and produced new substances,and changed the pore characteristics of coal under the action of water wedge and drying.In the practice of coal seam acidification,cleaning should be carried out in time to avoid re-solidification of reactants after water loss and plugging of pores.
作者
肖知国
郝梅
唐志昊
刘永强
钱程
XIAO Zhiguo;HAO Mei;TANG Zhihao;LIU Yongqiang;QIAN Cheng(School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo 454003,China;State Key Laboratory Cultivation Base for Gas Geology and Gas Control,Henan Polytechnic University,Jiaozuo 454003,China;Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization,Jiaozuo 454003,China)
出处
《煤炭科学技术》
CSCD
北大核心
2024年第S2期79-87,共9页
Coal Science and Technology
基金
国家自然科学基金资助项目(52274186,51204066)。
关键词
酸化
气润湿反转
瓦斯
煤吸附特性
水锁效应
acidification
gas wetting reversal
gas
characteristics of coal
water blocking effect
