2012 Half Year Results Presentation - Antofagasta plc

• Centinela Mining District feasibility study commenced at the end of 2011• Feasibility study now envisages a phasing of the development of the District• Initial focus on the Esperanza Sur sulphide and Encuentro oxide projectso Esperanza SurPotential production of ~140kt of copper and 160koz of gold over first 10 years of operationPotential capex of ~$3.5bno Encuentro oxides Potential production of ~50kt per year for 8 years utilising El Tesoro SX-EW plant from 2016Potential capex of ~$0.6bn• Study expected to continue through into 2013 with possible approval of the projects in 2014• To be followed by Encuentro sulphide projecto Potential production of 140-160kt of copper and 160 -180koz of gold possibly from 2021Centinela Mining District(formerlySierra Gorda District)• Continuing exploration and drilling programme across the rest of the highly prospective Distrito be followed by the Encuentrosulphide project.Esperanza SurEncuentroPenacho Blanco19