1. School of Mining and Coal Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, P. R. China
2. Inner Mongolia Key Laboratory of Mining Engineering, Baotou 014010, P. R. China
3. Department of Mining Engineering, Mehran University of Engineering and Technology, Jamshoro 76062, Pakistan
4. Collaborative Innovation Center of Integrated Exploitation of Bayan Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010, P. R. China