1. Department of Systems and Industrial Engineering, University of Arizona, 1127 East James E. Rogers Way, Tucson 85721, AZ, USA
2. Robert M. Buchan Department of Mining, Queen's University, 25 Union Street, Kingston, ON K7L 3N6, Canada
3. Critical Materials Institute, Ames National Laboratory, US Department of Energy, Ames, IA, 50011, USA
4. The Lubrizol Corporation, Cleveland, OH, 44141, USA