•  
  •  
 

Coal Geology & Exploration

Abstract

The identification of the burning temperature of burnt rocks has important guiding significance for the formation and evolution of burnt rocks. Based on the thermal Kaiser effect, the threshold temperature of burnt rock in Zhangjiamao, Shenmu, Northern Shaanxi Province is predicted through the acoustic emission (AE) acumulated energy and the changes of parameters RA (rise time/amplitude) and AF (average frequency) during heat treatment. The results show that the thermoacoustic emission characteristics of burnt rocks can effectively identify the burning temperature of burnt rocks, and it is basically consistent with the petrographic analysis of the temperature experienced by the burnt rocks. There is a significant formation burning temperature gradient in the burnt rocks in the study area. For the rocks in the first to the fifth layers, the burning threshold temperature increases gradually; for the sixth to the seventh layers of rock, the maximum temperature exceeds 700℃; for the eighth layer of rock, the threshold temperature is 245℃. When the heat treatment temperature is low, the intergranular tensile cracks develop in the rock. When the temperature exceeds 600℃, the proportion of transgranular shear cracks begins to increase, and the AE signal increases twice. At the same time, there is a quiet period of AE, and there are multiple platforms in the cumulative energy curve. The identification and zoning of burning temperature of burnt rocks, it has important practical significance for water control of coal mine and stability of surrounding rock.

Keywords

burnt rock, threshold temperature, thermal Kaiser effect, accumulated energy, RA value, AF value

DOI

10.12363/issn.1001-1986.21.09.0490

Reference

[1] 赵宇,闫飞. 霍林河一、二号露天区烧变岩的形成[J]. 煤炭技术,2005,24(4):99−100. ZHAO Yu,YAN Fei. Analysis on the form of burn–change rock in Huolinhe open–cut No.1 and No.2 mining area[J]. Coal Technology,2005,24(4):99−100.

[2] 范立民,蒋泽泉. 烧变岩地下水的形成及保水采煤新思路[J]. 煤炭工程,2006(4):40−41. FAN Limin,JIANG Zequan. Formation of underground water bellow burnt rock and new conception of coal mining with water conservation[J]. Coal Engineering,2006(4):40−41.

[3] FOIT F F JR,ROSENBERG P E,HOOPER R L. An unusual pyroxene,melilite,and iron oxide mineral assemblage in a coal−fire buchite from Buffalo,Wyoming[J]. American Mineralogist,1987,72(1/2):137−147.

[4] COSCA M A,ESSENE E J,GEISSMAN J W,et al. Pyrometamorphic rocks associated with naturally burned coal beds,Powder River Basin,Wyoming[J]. American Mineralogist,1989,74(1/2):85−100.

[5] 孙德全,鲁孟胜,张兆民. 新疆大南湖北露天煤矿首采区Ⅲ火烧区地下水资源的数值模拟[J]. 煤田地质与勘探,2014,42(4):64−68. SUN Dequan,LU Mengsheng,ZHANG Zhaomin. The numerical simulation of groundwater resources in burnt zone of the first mining area Ⅲ in Dananhu northern surface mine of Xinjiang[J]. Coal Geology & Exploration,2014,42(4):64−68.

[6] NOLTER M A,VICE D H. Looking back at the Centralia coal fire:A synopsis of its present status[J]. International Journal of Coal Geology,2004,59(1/2):99−106.

[7] WHITEHOUSE A E,MULYANA A A S. Coal fires in Indonesia[J]. International Journal of Coal Geology,2004,59(1/2):91−97.

[8] PRAKASH A,GUPTA R P,SARAF A K. A Landsat TM based comparative study of surface and subsurface fires in the Jharia coalfield,India[J]. International Journal of Remote Sensing,1997,18(11):2463−2469.

[9] ELLYETT C D,FLEMING A W. Thermal infrared imagery of the Burning Mountain coal fire[J]. Remote Sensing of Environment,1974,3(1):79−86.

[10] GOREE W S,FULLER M. Magnetometers using RF−driven squids and their applications in rock magnetism and paleomagnetism[J]. Reviews of Geophysics,1976,14(4):591−608.

[11] LINDQVIST J K,HATHERTON T,MUMME T C. Magnetic anomalies resulting from baked sediments over burnt coal seams in southern New Zealand[J]. New Zealand Journal of Geology and Geophysics,1985,28(3):405−412.

[12] SOKOL E,VOLKOVA N. Combustion metamorphic events resulting from natural coal fires[J]. Reviews in Engineering Geology,2007,18:97−115.

[13] GAVSHIN V M,MIROSHNICHENKO L V. Uranium concentration in altered brown coals located under burnt rocks from the Kansk–Achinsk basin,west Siberia,Russia[J]. Fuel and Energy Abstracts,2002,43(3):168.

[14] SOKOL E,VOLKOVA N,LEPEZIN G. Mineralogy of pyrometamorphic rocks associated with naturally burned coal–bearing spoil heaps of the Chelyabinsk coal basin,Russia[J]. European Journal of Mineralogy,1998,10(5):1003−1014.

[15] 刘同庆,杨雪,徐克全. 大南湖二号煤矿烧变岩疏干井水文地质参数差异性分析[J]. 山东煤炭科技,2015(6):175−176. LIU Tongqing,YANG Xue,XU Kequan. The difference analysis of hydrogeological parameter of burnt rock unwatering well in Dananhu No.2 mine[J]. Shandong Coal Science and Technology,2015(6):175−176.

[16] 牛建国. 神府矿区活鸡兔矿井烧变岩水文地质特征[J]. 煤田地质与勘探,2001,29(1):37−39. NIU Jianguo. Hydrogeological characteristics of burnt rock in Huojitu mine,Shenfu mining area[J]. Coal Geology & Exploration,2001,29(1):37−39.

[17] 李林. 神东矿区煤矿水害及其防治研究[J]. 煤田地质与勘探,2004,32(增刊1):128−130. LI Lin. Water hazard control in Shendong coal mining area[J]. Coal Geology & Exploration,2004,32(Sup.1):128−130.

[18] 李曼,刘天佑. 煤田烧变岩非均匀磁化的二度半模型反演[J]. 煤田地质与勘探,2006,34(2):67−69. LI Man,LIU Tianyou. Variable magnetization interactive inversion method by 2.5 D for burnt coal[J]. Coal Geology and Exploration,2006,34(2):67−69.

[19] 管海晏,冯·享特伦,谭永杰,等. 中国北方煤田自燃环境调查与研究[M]. 北京:煤炭工业出版社,1998.

[20] 刘志伟. 陕北地区烧变岩的地质特性与工程性能分析[J]. 电力勘测设计,2005(2):27−30. LIU Zhiwei. Geological characteristic analysis and engineering property of baked metamorphic rock in north Shanxi region[J]. Electric Power Survey & Design,2005(2):27−30.

[21] 范立民. 生态脆弱区烧变岩研究现状及方向[J]. 西北地质,2010,43(3):57−65. FAN Limin. Research status and research directions of burnt rocks in vulnerable ecological region[J]. Northwestern Geology,2010,43(3):57−65.

[22] BUONASERA T. Fatty acid analysis of prehistoric burned rocks:a case study from central California[J]. Journal of Archaeological Science,2005,32(6):957−965.

[23] DOBOSZ B,KRZYMINIEWSKI R. Characteristic of paramagnetic centres in burnt clay and pottery by the EPR method[J]. Radiation measurements,2007,42(2):213−219.

[24] CIESIELCZUK J,KRUSZEWSKI Ł,MAJKA J. Comparative mineralogical study of thermally–altered coal–dump waste,natural rocks and the products of laboratory heating experiments[J]. International Journal of Coal Geology,2015,139:114−141.

[25] SHARYGIN V V. Mayenite–supergroup minerals from burned dump of the Chelyabinsk coal basin[J]. Russian Geology and Geophysics,2015,56(11):1603−1621.

[26] RHODES S E,WALKER M J,López-Jiménez A,et al. Fire in the early Palaeolithic:Evidence from burnt small mammal bones at Cueva Negra del Estrecho del Río Quípar,Murcia,Spain[J]. Journal of Archaeological Science:Reports,2016,9:427−436.

[27] MORRISS M C,WEGMANN K W. Geomorphology of the burnt river,eastern Oregon,USA:Topographic adjustments to tectonic and dynamic deformation[J]. Geomorphology,2017,278:43−59.

[28] 时志强,杨小康,王艳艳,等. 含煤盆地表生热液铀成矿理论及证据:以伊犁盆地南缘及鄂尔多斯盆地东北部侏罗系为例[J]. 成都理工大学学报(自然科学版),2016,43(6):703−718. SHI Zhiqiang,YANG Xiaokang,WANG Yanyan,et al. Theory of uranium mineralization caused by supergene hydrothermal fluid in coal–bearing basins:Evidences from Jurassic sandstone in southern Yili Basin and northeastern Ordos Basin,China[J]. Journal of Chengdu University of Technology(Science & Technology Edition),2016,43(6):703−718.

[29] 席道瑛,陈普刚. 应力或热疲劳对花岗岩凯塞效应的影响[J]. 地震地质,1995,17(2):162−166. XI Daoying,CHEN Pugang. On influence of stress and thermal fatigue on Kaiser effects of granite[J]. Seismology and Geology,1995,17(2):162−166.

[30] LAVROV A. The Kaiser effect in rocks:Principles and stress estimation techniques[J]. International Journal of Rock Mechanics & Mining Sciences,2003,40(2):151−171.

[31] 席道瑛,程经毅,黄建华. 声发射在研究岩石古温度中的应用[J]. 中国科学技术大学学报,1996,26(1):97−101. XI Daoying,CHENG Jingyi,HUANG Jianhua. The application of acoustic emission in the study of ancient temperature of rock[J]. Journal of China University of Science and Technology,1996,26(1):97−101.

[32] 张建坤,何生,易积正,等. 岩石热声发射和盆模技术研究中扬子区西部下古生界海相页岩最高古地温和热成熟史[J]. 石油学报,2014,35(1):58−67. ZHANG Jiankun,HE Sheng,YI Jizheng,et al. Rock thermo–acoustic emission and basin modeling technologies applied to the study of maximum paleotemperatures and thermal maturity histories of Lower Paleozoic marine shales in the western middle Yangtze area[J]. Acta Petrolei Sinica,2014,35(1):58−67.

[33] 李佳蔚,邱楠生,梅庆华,等. 利用热声发射技术测量岩石最高古温度的探索[J]. 地球物理学报,2011,54(11):2898−2905. LI Jiawei,QIU Nansheng,MEI Qinghua,et al. Study on measuring the highest rock paleotemperature with thermo–acoustic emission[J]. Chinese Journal of Geophysics,2011,54(11):2898−2905.

[34] 武晋文,陈淑萍. 升温和降温对无约束花岗岩热破裂的影响[J]. 地下空间与工程学报,2019,15(1):108−115. WU Jinwen,CHEN Shuping. Effect of heating and cooling on thermal cracking of granite under unconstrained conditions[J]. Chinese Journal of Underground Space and Engineering,2019,15(1):108−115.

[35] 周逸飞,朱星,刘文德. 基于声发射和高斯混合模型的灰岩破裂特征识别研究[J]. 水利水电技术,2019,50(11):131−140. ZHOU Yifei,ZHU Xing,LIU Wende. Identification of cracking characteristics of limestone under uniaxial compression condition using acoustic emission and GMM[J]. Water Resources and Hydropower Engineering,2019,50(11):131−140.

[36] 肖旸,周一峰,马砺,等. 热–力作用对岩石热破坏模式及其阈值影响的数值模拟[J]. 西安科技大学学报,2017,37(5):630−635. XIAO Yang,ZHOU Yifeng,MA Li,et al. Numerical simulation on effect of temperature−pressure on the failure mode and threshold of the rock[J]. Journal of Xi’an University of Science and Technology,2017,37(5):630−635.

[37] 刘长龄. 论烧变矿床与烧变岩研究及其意义[J]. 地质找矿论丛,1988,3(3):54−61. LIU Changling. On study of burnt deposits and burnt rocks and their significance[J]. Contributions to Geology and Mineral Resources Research,1988,3(3):54−61.

[38] 杜中宁,党学亚,卢娜. 陕北能源化工基地烧变岩的分布特征及水文地质意义[J]. 地质通报,2008,27(8):1168−1172. DU Zhongning,DANG Xueya,LU Na. Distribution characteristics of burnt metamorphic rocks in the northern Shaanxi energy and chemical industry base,China and their hydrogeological significance[J]. Geological Bulletin of China,2008,27(8):1168−1172.

[39] 侯恩科,童仁剑,冯洁,等. 烧变岩富水特征与采动水量损失预计[J]. 煤炭学报,2017,42(1):175−182. HOU Enke,TONG Renjian,FENG Jie,et al. Water enrichment characteristics of burnt rock and prediction on water loss caused by coal mining[J]. Journal of China Coal Society,2017,42(1):175−182.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.