1. iThemba LABS National Research Foundation PO Box 722 Somerset West 7129 South Africa
2. Faculty of Physics & Applied Computer Science AGH University of Science and Technology Al. A. Mickiewicza 30 Krakow 30‐059 Poland
3. Centre for Mined Land Rehabilitation Sustainable Minerals Institute The University of Queensland St Lucia Qld 4072 Australia
4. Université de Lorraine – INRA Laboratoire Sols et Environnement, UMR 1120 Nancy France