Research on the combustion characteristics of coal with different degrees of high-temperature oxidation

ABSTRACT

In view of the possibility of reignition of coal through inhibited oxidation reactions after contact with oxygen, the oxidation characteristics of coal at different oxidation degrees were studied using a self-built oxidation experiment system as well as ESR and FTIR instruments. The results indicated that the oxygen consumption rate and formation rate of carbon and oxygen gases increased rapidly in the range of 210°C to 430°C, the oxidation rate slowed down when the coal was pre-oxidized at 180°C, and the oxidation rate reached the maximum at 330°C as well as 380°C. When the final temperature of the coal samples reburning at 230°C and 330°C was 430°C, the difference among g factor, line width, and free radical concentration was the largest. With the increase in oxidation degree, the maximum difference of C-O peak area was 14.3%, the maximum difference of OH area was 1.1%, and the maximum difference of C=O area was 18.8%. When the peak area ratio of functional groups turned over, the preoxidation temperature was higher than 230°C. With the increase of the preoxidation temperature, the oxidation activity of coal was enhanced, and spontaneous combustion was more likely to occur. The research findings hold theoretical significance for ensuring safe fire zone opening procedures and preventing reignition in coal mine fire areas.

KEYWORDS:

• High-temperature oxidation
• inerting reignition
• oxidation characteristics
• free radical
• functional group

Disclosure statement

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

Additional information

Notes on contributors

Yudie Zhang

Yudie Zhang received the B.S. degree in safety engineering from Anhui University of Technology, Maanshan City, Anhui Province, China, in 2022 . She is currently working toward the M.S. degree in resource and environment with the safety engineering,School of Safety Engineering, China University of Mining and Technology, Xuzhou, China.Her research interests includecoal spontaneous combustion and Gas control.

Shengqiang Yang

Shengqiang Yang, graduated from the Underground mining major of China University of Mining and Technology in 1984, and graduated from the Safety Technology and Engineering major of China University of Mining and Technology in 2000. His research direction is gas extraction and control, spontaneous combustion fire law and control.

Hanting Jiang

Hanting Jiang received the B.S. degree in safety engineering from Shenyang Aerospace University, Shenyang City in Liaoning Province, China, in 2023 . He is currently working toward the M.S. degree in safety engineering with the safety engineering, School of Safety Engineering, China University of Mining and Technology, Xuzhou, China.His research interests includecoal spontaneous combustion and big data