Study on oxidation characteristics of coal gangue with different moisture content under water immersion drying
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摘要:
露天堆积的煤矸石受雨水浸泡发生变化,在不同降水量区域表现出具有差异性的自燃倾向。为了研究水分对煤矸石氧化自燃的作用和影响,采用内蒙古棋盘井地区易自燃中高硫煤矸石进行研究。首先,对煤矸石进行不同浸水率(0、15%、30%、50%、100%)的浸泡试验,浸泡45 d后对煤矸石进行自然风干;将干燥后的矸石样品放入自制程序升温试验炉进行升温试验(升温速率设置为3 ℃/min,升温范围设置为30~390 ℃),使用集气袋收集煤矸石在各阶段温度点的气体(以每升高15 ℃为1个阶段),最后将采集气体通入GC-4000A型气相色谱仪。通过对比煤矸石在不同浸水率处理后的O2消耗及CO、CH4、C2H4、C2H6等指标气体生成的体积分数变化,结果表明:煤矸石在浸水率为15%时的低温氧化特性最佳,CO、CH4、C2H4、C2H6等指标气体初始生成温度最低,当温度在390 ℃时产生各类指标气体体积分数最大;当浸水率超过50%时,在水分的溶解作用下,煤矸石中大量可燃物质被水分携带逸散,导致该浸水率煤矸石升温至390 ℃时生成的各类指标气体体积分数显著降低,甚至低于未经过浸水复干处理的对照试验组;煤矸石在水分的浸泡作用下,生成各类指标气体的初始温度点均降低约15 ℃。
Abstract:Coal gangue, which accumulates in the open air, is modified by immersion in rain, and exhibits different tendencies to spontaneous combustion in different areas of precipitation. To study the role and influence of moisture on the oxidation and spontaneous combustion of coal gangue, we used high-sulfur coal gangue prone to spontaneous combustion in the Qipanjing area of Inner Mongolia. First, the coal gangue is soaked with different moisture content (moisture content: 0, 15%, 30%, 50%, 100%). After soaking for 45 days, the coal gangue is naturally air dried. The dried gangue samples were put into the self-made programmed temperature experiment furnace to conduct experiments on the pre-treated coal gangue samples (the temperature rise rate was set at 3℃/min, and the temperature rise range was set at 30−390 ℃). The gas the temperature points of the coal gangue in each stage was collected by air collecting bag (each rise of 15 ℃ was a stage). Finally, the collected gas was passed into the GC-4000A gas chromatograph. By comparing the O2 consumption、the volume fraction of CO, CH4, C2H4, C2H6 and other index gases produced by coal gangue treated with different moisture content, the results show that: The low temperature oxidation of coal gangue is the best when the moisture content is 15%, the initial formation temperature of CO, CH4, C2H4, C2H6 and other indicator gases is the lowest, and the concentration of various indicator gases is the highest when the temperature is 390℃. When the moisture content exceeds 50%, under the action of moisture dissolution, a large number of combustible substances in the coal gangue are carried and dispersed by moisture, resulting in a significant decrease in the concentration of various indicator gases generated when the moisture content of the coal gangue rises to 390 ℃, even lower than that of the control experimental group without moisture immersion and redrying treatment. When the coal gangue is immersed in water, the initial temperature points of the various index gases are reduced by about 15 ℃.
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Keywords:
- water immersion drying /
- coal gangue /
- oxidation /
- spontaneous combustion /
- program heats up /
- indicator gas
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0. 引 言
我国1 500~3 000 m的煤层气地质资源量约为30.37×1012 m3,为1 500 m以浅煤层气资源量的2倍[1-2]。随着深部煤层气勘探开发深入,游离气含量受到关注,游离气含量高的干煤系统中具有见气时间早、见气产量高的特点[2]。游离气的保存除了受煤岩的自封闭作用,顶板的封盖性也是重要的影响因素。煤层气富集受构造特征影响明显,在鄂尔多斯盆地东缘发育有缓倾斜、单斜、背斜、向斜、推覆构造、逆断层和挤压型层滑等7种有利的富气构造[3]。不同微构造部位的煤层含气性、渗透性、压裂改造效果和气水产出存在明显差异,同时构造高部位会形成动态气藏,影响煤层气开发全周期[4]。尽管煤层气是连续型的天然气藏,但是也具有“源岩控储”和“物性控藏”的特征,在高孔高渗区容易形成富集甜点[5]。可见,顶板封盖性是影响煤层气聚集的重要影响因素,关联和影响甜点区优选和开发井网设计。
煤层直接顶板包括泥岩、灰岩和砂岩等,均可以形成封盖条件,但是具体封盖效果受裂缝发育情况、储层物性等因素综合影响。通过鄂尔多斯盆地的煤层气和煤层邻近致密气勘探开发证实,部分地区煤层直接顶板砂岩具有良好含气性,开发效果优于远距离砂岩[6]。深浅侧向、密度、声波时差和补偿中子等测井数据可以构建孔隙率和裂缝模型来评价顶底板封盖条件,形成了结合测井动态弹性模量和岩心静态结合的裂缝强度指数计算模型[7]。地震数据也可以用来解释顶板岩性和封盖性,但是总体精度不高,很难解释微小构造变化影响的煤层顶板差异。微电阻率成像测井可以采集更多地层信息,且处理后的动态图像可以直观反映裂缝发育情况等信息[8-11]。裂缝的发育方向可以指示地应力的方向,地应力研究对地质与工程具有重要的意义,可为后期的压裂射孔措施提供有效依据,提高工程作业质量和效率[12-16]。
为推动煤层开发地区深部煤层气勘探开发突破,笔者基于微电阻率成像测井手段,刻画不同岩性在成像测井上的响应特征,建立顶板岩性识别图版;明确高导缝与诱导缝在成像测井上的识别特征,分析煤层顶板裂缝发育情况;进一步结合顶板岩性、厚度与裂缝发育情况等,划分不同封盖性的煤层顶板组合条件类型,相关工作可以有效支撑深部煤层气甜点区带优选和井位部署。
1. 区域地质背景
鄂尔多斯盆地总面积约为25×104 km2,横跨山西、陕西两省,整体轮廓呈现矩形,构造位置属于华北地台西部。盆地内划分6个二级构造单元,包括伊盟隆起、渭北隆起、晋西挠褶带、天环坳陷、西缘冲断带以及伊陕斜坡[17-20]。本文所用钻井和测井数据主要来自于鄂尔多斯盆地东北缘,构造上属于晋西挠褶带,整体为单斜构造,地层倾角小[20]。鄂尔多斯盆地整体发育太原组和山西组2套主力煤层,下部太原组的8号煤层及其顶板是此次分析重点。
2. 顶板岩性识别
利用电成像测井,可以较为精确地识别煤层顶板岩性,评价顶板裂缝发育情况与连通性,为煤层及顶板封盖性精细评价提供有利支撑。综合参考钻井取心资料、常规测井图像特征等划分岩性,共识别出砾岩、粗砂岩、中砂岩、细砂岩、粉砂岩、泥质粉砂岩(砂质泥岩)、碳质泥岩、泥岩、灰岩及煤等10种岩性(图1)。
综合常规测井资料与电成像特征等,对以上10种岩性的特征进行了系统总结。砾岩,常规测井曲线上GR为低值,密度一般在1.5~4.5 g/cm3,声波时差较低,电成像静态图像以暗色、褐色为主,动态图像上可具有亮色斑点状特征,发育块状层理;粗砂岩,GR为低值,密度通常在2.5 g/cm3,声波时差较高,静态图像呈暗色,动态图像上发育交错层理,具有砂质感;中砂岩,GR为低值,密度介于2.2~2.8 g/cm3,声波时差较高,静态图像上呈暗色,动态图像上发育交错层理,砂质感较粗砂岩略细;细砂岩,GR为低值,密度一般大于2.4 g/cm3,声波时差较高,静态图像以黄褐色为主,动态图像上发育交错层理,层理细腻,颗粒感较差;粉砂岩,GR值较高,密度介于2.0~2.4 g/cm3,声波时差较高,静态态图像以橘黄色为主,动态图像上发育波状层理;泥质粉砂岩(砂质泥岩),GR较高,密度介于2.6~2.9 g/cm3,声波时差较高,静态图像上以亮黄色或亮白色为主,可见暗色或黄色块状,动态图像上可见黄色斑点和亮色条带;碳质泥岩,GR为高值,密度介于2.66~2.77 g/cm3,声波时差较高,静态图像以黄褐色为主,动态图像上发育水平层理,见亮色条带及黑色斑点;泥岩,GR为高值,密度介于2.2~2.7 g/cm3,声波时差高,静态图像以亮黄色为主,动态图像上发育水平层理,见白色条带;灰岩,GR为低值,密度一般为2.7 g/cm3,声波时差较高,静态图像上呈亮色,动态图像上呈层状特征;煤,GR为低值,密度介于1.3~1.4 g/cm3,声波时差较高,静态图像呈亮色,动态图像上呈层状、块状特征。可总结出如下规律:碎屑岩静态图像由亮变暗,泥岩最亮,砾岩最暗。通过对该区深煤层顶板岩性的识别统计发现,煤层的顶板岩性大部分为泥岩,约占78%,其次为砂岩,约占15%,灰岩和其他岩性发育较少(图2)。
3. 裂缝类型识别及应用
煤层顶板裂缝会影响力学性能与渗透率,降低顶板岩石强度,导致煤层气逸散等情况,降低封盖能力,不利于煤层气的保存[21]。为评价深煤层顶板的封盖性优劣,需对裂缝的存在及裂缝的类型进行精确判断。基于成像测井资料对研究区内煤层顶板的裂缝发育情况进行综合分析可知,主要存在裂缝类型为构造缝与非构造缝,其中构造缝也称为天然裂缝,非构造缝也称为诱导缝,构造缝按充填特征可分为高导缝和高阻缝2类,高导缝充填物一般为泥质充填和黄铁矿充填等,高阻缝充填物一般为方解石、白云石和石英等非导电矿物。非构造缝缝根据成因可分为钻具震动缝、泥浆压裂缝、应力释放缝与井眼崩落,如图3所示。
构造缝与非构造缝在电成像上的成像特征有明显区别。构造缝在电成像图像上表现为较规则的正弦线,以高导缝为例(图4a),泥质充填缝表现为暗色连续的正弦曲线,缝面较规则,轻微溶蚀;张开缝表现为暗色断续的正弦曲线,缝面宽窄不一,局部有明显的溶蚀扩大现象。
诱导缝在电成像图像上多呈羽状,分布于对称的2条极板上。钻具振动缝在电成像图像上微小且延伸很短,呈羽毛状或雁行状(图4b);应力释放缝,表现为一组呈180°或接近180°对称分布的羽状纹理(图4c);井眼崩落,表现为2条较宽且呈180°或接近180°对称分布的暗色或黑色垂直条带或斑状(图4d);泥浆压裂缝,表现为2条呈180°或接近180°对称分布的黑色垂直条带,延伸较长,方向基本稳定。
诱导缝的形成与地应力有密切关系,因此借助诱导缝的发育方向可以有效判断地应力方向。通过对井壁应力进行分析,在最小水平主应力方向上有最大剪切应力。当应力超过岩石的抗剪强度,井壁就会产生崩塌。因此,井眼崩落的方向即为最小水平主应力方向(图5a)。由于裂缝较为发育,古构造应力大多被释放,地应力基本平衡,但在致密地层中裂缝不发育,且构造应力未被释放,因此地应力较大。当地层被钻开时,地应力释放,进而产生一组应力释放缝,该裂缝的方向即为最大水平主应力方向(图5b)。
4. 有利顶板组合条件
煤层含气量高低不仅受到煤层顶板封盖条件的影响,还受到煤岩演化程度、构造条件、水动力条件、地应力条件等地质因素综合影响,此外,煤层顶板中存在的裂缝对其力学性能与纵向渗透率影响较大,导致顶板岩石强度降低,井眼失稳,以及煤层气逸散等情况出现,降低封盖能力,不利于煤层气保存,进而影响含气量[22]。但在同一地区,其他地质因素相似的情况下,煤层含气量主要与煤层顶板封盖性优劣有关,因此,需划分出有利的煤层顶板组合条件,为深部煤层气甜点区带优选和井位部署提供支撑(表1)。
表 1 煤层顶板组合条件分类Table 1. 1 Classification of coal seams and roof conditions级别 岩性特征 裂缝特征 厚度 含气量 静态图像 顶板厚度 直接顶板 岩性 裂缝 I 顶板以灰岩、泥岩等渗透性极差的
岩性为主,且厚度大裂缝发育很少或者基本无裂缝发育 大 高 亮色 厚 泥岩、灰岩 不发育 II 顶板以泥岩、碳质泥岩等渗透性极差的
岩性为主,但是厚度较薄由于厚度较薄,受诱导缝
影响易产生裂缝较大 较高 橘黄色 较薄 粉砂岩 较少 III 顶板岩性以砂岩为主 由于岩石强度较低,受诱导缝
影响易产生裂缝薄 低 褐色 薄 砂岩 发育 I类组合。顶板裂缝发育很少或者基本无裂缝发育, 此类顶板渗透性极差且厚度大,基本无裂缝发育,是最好的顶板封盖层。煤层厚度大(一般大于6 m),煤层含气量高(大于15 m3/t),在成像测井中,其静态图像呈现亮色,煤层直接顶板为泥岩、灰岩等,裂隙不发育(图6a)。II类组合。顶板层渗透性较差,但是厚度较薄,受诱导缝影响发育较孤立或细碎的裂缝。煤层厚度较大(3~6 m),煤层含气量较高(10~15 m3/t),在成像测井中,其静态图像呈现橘黄色,煤层直接顶板为粉砂岩,发育较少裂隙(图6b)。III类组合。顶板岩石在诱导缝的影响下裂缝发育。煤层较薄(小于3 m),煤层含气量较低(小于10 m3/t),在成像测井中,其静态图像呈现褐色,煤层直接顶板为砂岩,裂隙发育(图6c)。
5. 结 论
1)结合常规测井资料与微电阻率成像测井特征,基于静态电成像图可以有效区分砾岩、砂岩和泥岩等10类岩性,主要特征为碎屑岩静态图像由亮变暗,泥岩最亮,砾岩最暗,该煤层气开发地区煤层顶板以泥岩为主、砂岩次之。
2)煤层顶板裂缝主要发育有高导缝与诱导缝,高导缝包括张开缝和泥质充填缝,在成像图像上表现为正弦曲线;诱导缝可分为钻具震动缝、泥浆压裂缝、应力释放缝与井眼崩落,在成像图像上呈现为羽状或雁行状排列,可以用于判断地应力方向。
3)综合顶板岩性、厚度、裂缝发育情况等,该煤层气开发地区可划分出封盖性不同的3类煤层顶板组合,其中I类顶板电成像图像一般呈亮色且裂缝发育少;II类顶板发育较多裂隙;III类顶板图像显示裂隙切割且图像不清晰。
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表 1 煤矸石工业分析
Table 1 Industrial analysis of coal gangue
煤矸石
样品工业分析/% 全硫质量分数/% 硫化物硫质量分数/% 燃料比 水分 灰分 挥发分 固定碳 样品1 0.80 68.34 15.69 15.17 3.36 3.17 0.97 样品2 0.84 68.35 15.18 15.63 3.66 3.46 1.03 样品3 0.84 68.43 15.44 15.28 3.65 3.42 0.99 样品4 0.82 68.37 15.27 15.53 3.55 3.37 0.98 样品5 0.82 68.35 15.61 15.26 3.58 3.31 1.02 平均值 0.824 68.368 15.438 15.374 3.56 3.346 0.998 表 2 气相色谱仪气体最小检测浓度
Table 2 Gas chromatograph gas minimum detection concentration
气体类型 最小检测含量/(μL·L−1) $ {\text{CO}} $ 0.5 $ {\text{C}}{{\text{O}}_{\text{2}}} $ 2 $ {\text{C}}{{\text{H}}_{\text{4}}} $ 0.5 $ {{\text{C}}_{\text{2}}}{{\text{H}}_{\text{2}}} $ 0.5 $ {{\text{C}}_{\text{2}}}{{\text{H}}_{\text{4}}} $ 0.1 -
[1] 祁杰. 煤矿矸石场防灭火方法分析[J]. 煤炭科学技术,2017,45(S2):53−54. QI Jie. Analysis on method of fire prevention and extinguishing in coal mine[J]. Coal Science and Technology,2017,45(S2):53−54.
[2] 文虎,陆彦博,刘文永. 水浸煤二次氧化自燃危险性实验研究[J]. 矿业安全与环保,2020,47(3):6−11. WEN Hu,LU Yanbo,LIU Wenshui. Experimental study on the risk of secondary oxidation spontaneous combustion of water immersed coal[J]. Mining Safety and Environmental Protection,2020,47(3):6−11
[3] 蔡毅,严家平,陈孝杨,等. 表生作用下煤矸石风化特征研究——以淮南矿区为例[J]. 中国矿业大学学报,2015,44(5):937−943. CAI Yi,YAN Jiaping,CHEN Xiaoyang,et al. Weathering characteristics of coal gangue in hypergenesis:A case study on Huainan coal mining area[J]. Journal of China University of Mining & Technology,2015,44(5):937−943.
[4] 张清峰,王东权,于广云,等. 煤矸石风化对其物理力学性能影响的研究[J]. 中国矿业大学学报,2019,48(4):768−774. ZHANG Qingfeng,WANG Dongquan,YU Guangyun,et al. Research on the effect of weathering on physical and mechanical properties of coal gangue[J]. Journal of China University of Mining & Technology,2019,48(4):768−774.
[5] ZHAI X,GE H,WANG T,et al. Effect of water immersion on active functional groups and characteristic temperatures of bituminous coal[J]. Energy,2020(205),118076:1−12.
[6] YANG Y,LI Z,SI L,et al. Study governing the impact of long-term water immersion on coal spontaneous ignition[J]. Arabian Journal for Science and Engineering,2017,42:1359−1369. doi: 10.1007/s13369-016-2245-9
[7] 郭海桥,程伟,尚志,等. 水分和冻融循环对酷寒矿区煤矸石风化崩解速率影响的定量研究[J]. 煤炭学报,2019,44(12):3859−3864. GUO Haiqiao,CHENG Wei,SHANG Zhi,et al. Quantitative determination of the effect of moisture and freeze/thaw cycles on coal gaugue decay rate in severe cold mining areas[J]. Journal of China Coal Society,2019,44(12):3859−3864.
[8] STRACHER G B,PRAKASH A,SOKOL E V. Coal and peat fires[M]. London:Elsevier,2013.
[9] 邓军,李贝,肖旸,等. 基于热重-傅里叶红外光谱联用的煤矸石自燃特性及微观表征[J]. 西安科技大学学报,2017,37(1):1−6. DENG Jun,LI Bei,XIAO Yang,et al. Spontaneous combustion characteristics and micro characterization of coal gangue based on thermogravimetry-fourier tromsform infrared spectrometer[J]. Journal of Xi'an University of Science and Technology,2017,37(1):1−6.
[10] LEWIŃSKA P,DYCZKO A. Thermal digital terrain model of a coal spoil tip–a way of improving monitoring and early diagnostics of potential spontaneous combustion areas[J]. Journal of Ecological Engineering,2016,17(4):170−179. doi: 10.12911/22998993/64605
[11] 杜玉玺,苏未曰,吴媛婧,等. 自燃煤矸石山内部温度拟合与可视化研究[J]. 矿业安全与环保,2018,45(5):32−36. DU Yuxi,SU Weiyue,WU Yuanjing,et al. Study on fitting and visualization of internal temperature of spontaneous combustion gangue hill[J]. Mining Safety and Environmental Protection,2018,45(5):32−36.
[12] 吕志金,欧阳辉,秦清河,等. 补连塔煤矿22307采空区CO异常分析与治理[J]. 煤矿安全,2016,47(6):151−153. LV Zhijin,OU Yanghui,QIN Qinghe,et al. Analysis and treatment of co anomaly occurred in 22307 goaf of bulianta coal mine[J]. Safety in Coal Mines,2016,47(6):151−153.
[13] ZHANG J,WANG J,LI Z,et al. Molecular dynamics simulation and gas generation tracking of pyrolysis of bituminous coal[J]. ACS Omega,2022,7(13):11190−11199. doi: 10.1021/acsomega.2c00010
[14] 邓军,张扬,李成会,等. 水浸煤体自燃极限参数和氧化动力学的研究[J]. 煤炭技术,2016,35(3):152−154. DENG Jun,ZHANG Yang,LI Chenghui,et al. Research of limit parameters and oxidation kinetics of water-logging coal self-ignition[J]. Coal Technology,2016,35(3):152−154.
[15] 李锋,安世岗,邢真强. 水浸煤孔隙结构及自燃特性试验研究[J]. 煤炭科学技术,2019,47(S2):208−212. LI Feng,AN Shigang,XING Zhenqiang,et al. Experimental study on pore structure and spontaneous combustion characteristics of submerged coal[J]. Coal Science and Technology,2019,47(S2):208−212.
[16] 文虎,王栋,赵彦辉,等. 水浸煤体自燃特性实验研究[J]. 煤炭技术,2015,34(1):261−263. WEN Hu,WANG Dong,ZHAO Yanhui,et al. Experimental study on spontaneous combustion characteristics of water-immersed coal[J]. Coal Technology,2015,34(1):261−263.
[17] 褚廷湘,苏媛媛,陈月霞. 水分散失对破碎煤体空隙率变化的影响研究[J]. 河南理工大学学报(自然科学版),2023,42(3):42−49. CHU Tingxiang,SU Yuanyuan,CHEN Yuexia. Study on the influence of water losing on crushed coal porosity[J]. Journal of Henan Polytechnic University(Natural Science),2023,42(3):42−49.
[18] 郭胜利. 水浸煤氧化活性增强机理及其抑制研究[D]. 淮南:安徽理工大学,2022. GUO Shengli. Study on the mechanism of oxidation activity enhancement of water-soaked coal and its inhibition[D]. Huainan:AnHui University of Science and Technology,2022.
[19] 周新华,张建新,舒悦,等. 干湿交替对碱性煤矸石中重金属释放潜能影响及风险评价[J]. 安全与环境学报,2023,23(6):2137−2144. ZHOU Xinhua,ZHANG Jianxin,SHU Yue,et al. Release potential and risk assessment of heavy metals from alkaline coal gangue under drying-wetting cycles[J]. Journal of Safety and Environment,2023,23(6):2137−2144.
[20] MA L,ZOU L,REN L,et al. Prediction indices and limiting parameters of coal spontaneous combustion in the Huainan mining area in China[J]. Fuel,2020(264),116883:1−10.
[21] XIANCHUN L I,HUI S,QI W,et al. Experimental study on drying and moisture re-adsorption kinetics of an Indonesian low rank coal[J]. Journal of Environmental Sciences,2009,21:127−130. doi: 10.1016/S1001-0742(09)60022-X
[22] ZHENG Y,LI Q,LIN B,et al. Real-time analysis of the changing trends of functional groups and corresponding gas generated law during coal spontaneous combustion[J]. Fuel Processing Technology,2020(199),106237:1−10.
[23] 李宗翔,张明乾,杨志斌,等. 断层构造对煤结构及氧化自燃特性的影响[J]. 煤炭学报,2023,48(3):1246−1254. LI Zongxiang,ZHANG Mingqian,YANG Zhibin,et al. Effect of fault structure on the structure and oxidative spontaneous combustion characteristics of coal[J]. Journal of China Coal Society,2023,48(3):1246−1254.
[24] 陈晓坤,易欣,邓军. 煤特征放热强度的实验研究[J]. 煤炭学报,2005,30(5):81−84. CHEN Xiaokun,YI Xin,DENG Jun. Experiment study of characteristic self-heating intensity of coal[J]. Journal of China Coal Society,2005,30(5):81−84.
[25] 周雪雨,郭亮亮,张永波. 煤矸石人工热储的建造及自燃热能潜力分析[J]. 矿业安全与环保,2023,50(3):129−135. ZHOU Xueyu,GUO Liangliang,ZHANG Yongbo. Constraction of coal gangue artificial thermal storage and analysis of spontaneous combustion thermal energy potential[J]. Mining Safety & Environmental Protection,2023,50(3):129−135.
[26] 司磊磊,席宇君,王洪洋,等. 水浸干燥后煤的孔隙结构及瓦斯吸附特性变化规律[J]. 煤田地质与勘探,2021,49(1):100−107. SI Leilei,XI Yujun,WANG Hongyang,et al. The characteristics of pore structure and gas adsorption for water-immersion coal after drying[J]. Coal Geology & Exploration,2021,49(1):100−107.
[27] WEN G,YANG S,LIU Y,et al. Influence of water soaking on swelling and microcharacteristics of coal[J]. Energy Science & Engineering,2020,8(1):50−60.
[28] SONG S,QIN B,XIN H,et al. Exploring effect of water immersion on the structure and low-temperature oxidation of coal:A case study of Shendong long flame coal,China[J]. Fuel,2018,234:732−737. doi: 10.1016/j.fuel.2018.07.074
[29] 周西华,宋东平,聂荣山,等. 褐煤燃烧阶段碳氧化物生成规律研究[J]. 中国安全科学学报,2016,26(3):59−63. ZHOU Xihua,SONG Dongping,NIE Rongshan,et al. Study on formation law of carbon oxides of lignite in combustion phase[J]. China Safety Science Journal,2016,26(3):59−63.
[30] 王思栋,刘英忠,徐超. 煤矸石自燃氧化过程中自由基变化规律研究[J]. 工矿自动化,2020,46(4):34−37. WANG Sidong,LIU Yingzhong,XU Chao. Research on free radical variation law in spontaneous combustion and oxidation process of coal gangue[J]. Industry and Mine Automation,2020,46(4):34−37.
[31] 张磊,陆超,汪后港,等. 水分对煤炭低温氧化温升特性影响的研究[J]. 煤炭技术,2016,35(12):198−199. ZHANG Lei,LU Chao,WANG Hougang. Research on influence of moisture on low-temperature oxidation heating rate characteristics of coal[J]. Coal Technology,2016,35(12):198−199.
[32] 周西华,白刚,聂荣山,等. 褐煤燃烧阶段烃生成规律研究[J]. 中国安全科学学报,2016,26(1):58−63. ZHOU Xihua,BAI Gang,NIE Rongshan,et al. Study on generating rule of hydrocarbons at lignite combustion stage[J]. China Safety Science Journal,2016,26(1):58−63.
[33] 李林,陈军朝,姜德义,等. 煤自燃全过程高温区域及指标气体时空变化实验研究[J]. 煤炭学报,2016,41(2):444−450. LI Lin,CHEN Junchao,JIANG Deyi,et al. Experimental study on temporal variation of high temperature region and index gas of coal spontaneous combustion[J]. Journal of China Coal Society,2016,41(2):444−450.