Minera Centinela S.A., one of the biggest mining companies in Chile, was created through the integration of El Tesoro and Esperanza operations. Esperanza is a gold and copper mine located in Chile's northern region of Antofagasta (II), with reserves estimated at 587Mt grading 0.53% copper and 0.22g/t gold. Esperanza has an 18-year mine life. El Tesoro's mining operations comprise three open pits: Tesoro Central, Mirador and Tesoro Noreste. Minera Centinela is part of the Antofagasta Minerals group, which is engaged in copper exploration, production and sale.