Study on coal spontaneous combustion at low-medium temperature in the same coal seam with different buried depths and protolith temperatures

ABSTRACT

In the process of coal formation at deep coal seam, the coal quality changes by geological environment. Under the influence of high-temperature and surrounding heat storage conditions, the combined capacity of coal and oxygen is enhanced, and the risk of coal spontaneous combustion is enhanced. Based on the spontaneous combustion law of coal in deep high-temperature and thermal environment, industrial analysis and correlation analysis of coal samples with different buried depth in the same coal seam were carried out. The low-medium temperature oxidation laws of different coal samples were studied by infrared spectroscopy (IR) and thermogravimetric analysis. Industrial analysis and correlation analysis showed that the buried depth of coal samples was significantly correlated with protolith temperature and water content. The infrared spectrum analysis of coal samples showed that with the increase in buried depth, the oxygen-containing functional groups in coal structure increased so the tendency of spontaneous combustion of deep coal seam was greater. Thermogravimetric analysis showed that the low medium temperature oxidation process of coal samples could be divided into three stages. Compared with the shallow coal seam, the deep coal seam changes smoothly in the first two stages, and dramatically in the last stage.

KEYWORDS:

• Buried depth
• low-medium temperature oxidation
• coal spontaneous combustion
• infrared spectroscopy
• thermogravimetric analysis

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the Open Fond Research Project of the State Key Laboratory of Mining Disaster Prevention and Control, co-founded by Shandong Province [grant No. MDPC2016ZR04]; the Open Projects of Research Center of Coal Resources Safety Mining and Clean Utilization, liaoning [grant No. LNTU15KF15].