1. School of Mines, School of Resources and Geosciences, China University of Mining & Technology, Xuzhou, China
2. Key Laboratory of Deep Coal Resource Mining, School of Mines, China University of Mining & Technology, Xuzhou, China
3. State Key Laboratory of Coal Resources and Safe Mining, China University of Mining & Technology, Xuzhou, China
4. School of Minerals and Energy Resources Engineering, The University of New South Wales, Sydney, Australia