1. Department of Mining Exploitation and Prospecting, School of Mining, Energy and Materials Engineering, University of Oviedo, Independencia 13, 33004 Oviedo, Spain
2. Instituto Nacional de Silicosis, C/La Minería 1, 33011 Oviedo, Spain
3. Recuperación y Renovación SL, C/Santa Susana 29, 33007 Oviedo, Spain
4. Department of Mining, Industrial and ICT Engineering, Polytechnic University of Catalonia (UPC), Av. Bases de Manresa, 61-73, 08242 Manresa, Spain