1. College of Mining Engineering, Taiyuan University of Technology; Taiyuan Shanxi China
2. Green Mining Engineering Technology Research Center of Shanxi Province; Taiyuan Shanxi China
3. Institute of Mining Technology, Taiyuan University of Technology; Taiyuan China
4. Shanxi Blue Flame Coalbed Methane Refco Group Ltd and State Key Laboratory of Coal and Coalbed Methane Co-extraction; Jincheng, Shanxi China