1. Institute of Raw Material Preparation and Environmental Processing, University of Miskolc, Egyetemváros, H-3515 Miskolc, Hungary
2. Department of Minerals and Petroleum Engineering, University of Sao Paulo, Sao Paulo 05508-900, Sao Paulo, Brazil
3. Institute of Mineralogy and Geology, University of Miskolc, Egyetemváros, H-3515 Miskolc, Hungary