1. School of Chemistry and Environmental EngineeringChina University of Mining and Technology (Beijing) Beijing 100083 China
2. Tiandi (Tangshan) Mining Technology Co., Ltd. Tangshan 063000 Hebei China
3. Chinese National Engineering Research Center of Coal Preparation and PurificationChina University of Mining and Technology Xuzhou 221116 Jiangsu China
4. Henan Province Industrial Technology Research Institute of Resources and MaterialsZhengzhou University Zhengzhou 450001 China