1. Metallurgical and Mining Engineering Department; Universidad Católica del Norte; Avenida Angamos 0610 Antofagasta 1240000 Chile
2. Civil Engineering Department; Universidad Politécnica de Cartagena; Cartagena 30203 Spain
3. Mining, Geologic and Cartographic Engineering Department; Universidad Politécnica de Cartagena; Cartagena 30203 Spain
4. Applied Physics Department; Universidad Politécnica de Cartagena; Cartagena 30203 Spain