1. Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu, China
2. School of Chemistry and Chemical Engineering, Xi’an University of Science and Technology, Xi’an, Shaanxi, China
3. Key Laboratory of Coal Resources Exploration and Comprehensive Utilization, M.L.R., Xi’an, Shaanxi, China