1. College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China
2. Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Mineral, Shandong University of Science and Technology, Qingdao 266590, China
3. Hebei Coal Research Institute Corporation Co., Ltd, Xingtai 054000, China
4. Ningxia Coal Science and Technology Research Institute Co., Ltd, Ningxia 750004, China