1. Department of Geoscience and Petroleum, Faculty of Engineering, Norwegian University of Science and Technology, 7031 Trondheim, Norway
2. Department of Mineral Processing Engineering, Istanbul Technical University, Istanbul, 34469 Maslak, Turkey
3. Maelgwyn Mineral Services Ltd., Ty Maelgwyn, 1A Gower Road, Cathays, Cardiff CF24 4PA, UK