1. Department of Processing, Helmholtz-Institute Freiberg for Resource Technology, Helmholtz-Zentrum Dresden-Rossendorf, Freiberg, Germany;
2. Department of Mineral Processing, Faculty of Mining, Hanoi University of Mining and Geology, Hanoi, Vietnam;
3. Institute of Mechanical Process Engineering and Mineral Processing, Technical University Bergakademie Freiberg, Freiberg, Germany