Mirador copper-gold project is a large-scale open-pit mining operation located in the Zamora-Chinchipe Province in southern Ecuador. It is the first industrial-scale copper project to be developed in the Andean country.
The project is owned and operated by Ecuacorriente, a subsidiary of state-owned Chinese consortium CRCC-Tongguan that comprises the Tongling Nonferrous Metals Group and the China Railway Construction Corporation (CRCC). The Chinese consortium has a 30-year mining concession at Mirador.
The Mirador project was previously undertaken by Corriente Resources which completed a feasibility study for a 25,000 tonnes per day (tpd) mining operation in 2005 and got the environmental impact assessment (EIA) for the project approved in May 2006. A feasibility study for 30,000tpd operation was completed in 2008.
The CRCC-Tongguan consortium acquired the Mirador project from Corriente Resources in May 2010 and commenced construction in 2012. The company invested approximately £1.12bn ($1.4bn) on the project that commenced copper production in June 2019. The first shipment of 22,000t of copper from the mine was exported to China in January 2020.
Although Ecuacorriente planned to ramp up the copper production capacity at Mirador to 94,000 tonnes per year, it had to scale back the operations to a minimum due to the outbreak of the Covid-19 pandemic in March 2020.
Location, geology, and mineralisation
The Mirador copper-gold project is located in the El Pangui Canton, in the Zamora-Chinchipe Province of Ecuador, near the Peruvian border, approximately 340km to the south of Quito and approximately 70km east-southeast of the city of Cuenca.
The mine covers approximately 2,995ha in the Cóndor mountain range in the Ecuadorean Amazon.
Matador is a porphyry copper-gold-silver deposit with mineralisation hosted by the Late Jurassic granite and porphyries of the Zamora Batholith. The mineralisation at the Mirador deposit is found to be disseminated and fine-fracture controlled chalcopyrite with supergene chalcocite increasing copper graded inside an enrichment blanket of varying thickness.
Copper, gold and silver reserves at Mirador
The Mirador open-pit mine is estimated to contain 3.2 million tonnes (Mt) of copper, 3.4 million ounces (Moz) of gold, and 27.1Moz of silver in proven and probable reserves.
Mining and ore processing
Mirador is a conventional open-pit mine involving a drill, blast, load, and haul operations.
The run-of-the-mine (ROM) ore is trucked to the nearby processing plant where it passes through a gyratory crusher, two-stage grinding in a semi-autogenous (SAG) mill and a ball mill, before entering the flotation circuit for the production of concentrate.
The obtained concentrate undergoes dewatering, thickening, and filtration, and the final concentrates containing 29.5% copper, 4.9 g/t gold and 58 g/t silver are transported to the port of Guayaquil for shipment to copper refining plants in China.
The current milling capacity of the processing plant is 30,000tpd which is planned to be increased to 60,000tpd eventually.
The water requirement for the processing plant is sourced from the Rio Wawayme.
AMEC and SNC-Lavalin were engaged in preparing the feasibility study reports for the project in 2005 and 2007.
Knight Piesold and Merit Consultants International provided design services for the tailing facility of the project.
Moose Mountain Technical Services (MMTS) provided mine plan, production schedule, mine operating costs and mine capital costs for the Mirador copper-gold project.