[1] Univ Catolica Norte, Dept Ingn Quim, Antofagasta 1270709, Chile
[2] LUT Univ, Sch Engn Sci, POB 20, FI-53851 Lappeenranta, Finland
[3] Univ Catolica Norte, Dept Ingn Metalurg & Minas, Antofagasta 1270709, Chile
[4] Univ Antofagasta, Dept Ingn Quim & Proc Minerales, Antofagasta 1270300, Chile