Overview
The La Coipa open pit mine is located in the Atacama Region of northern Chile. The mine operates three open pits: Ladera Ferellon, Coipa Norte and Puren.
Kinross acquired ownership interest in La Coipa upon completion of the combination with TVX on January 31, 2003. On December 21, 2007, Kinross purchased the remaining 50% from Goldcorp Inc. and became the operator.
2009 gold equivalent production of the mine was 231k oz and 2009 cost of sales was US$438/oz. 2009 Proven and probable reserves of mine was 1.1m oz. gold; 37.9m oz. silver.
Location
The La Coipa open pit mine is located in the Atacama Region of northern Chile, approximately 1,000 kilometres north of Santiago and 140 kilometres northwest of the community of Copiapó.
The earliest written information about La Coipa as a precious metal prospect dates back almost a century, when a small underground copper-silver mine was in operation about two kilometres southeast of the present day operations. Regional resources have been sporadically exploited since then, but the La Coipa area itself did not receive any attention from exploration geologists until the late 1970s.
The mine lies in the Domeyko Cordillera at an elevation of between 3,800 and 4,400 metres, the plant site being at 3,815 metres. Current and future mining operations are at elevations ranging from 4,040 metres to 4,390 metres.
Geology
The property is located in the northern Chilean Tertiary volcanic belt generally known as the Maricunga belt. The mineral deposits formed by the precipitation of gold and silver from the circulating mineral bearing hydrothermal fluids into fracture and breccia zones. These permeable zones are controlled by major faults.
Gold occurs in quartz with secondary oxides and jarosite. Mercury is common in all the deposits and occurs as calomel. Mining is confined to surface oxide altered portions. Mineralization at Coipa Norte and Brecha Norte, are both hosted in volcanics and sediments. Silver mineralization occurs mainly in volcanics but gold is preferentially hosted in sedimentary rocks.
The operation consists of five deposits known as Ladera-Farellon, Coipa Norte, Brecha Norte, Can-Can and Puren. This last deposit is located eight kilometers northwest of Ladera-Farellon, and it was recently discovered by the La Coipa exploration team. The Coipa Norte deposit is located about five kilometers north of Ladera-Farellon. The Brecha Norte deposit is located northeast of the Coipa Norte deposit.
Mining & Operation
The La Coipa mine consists of approximately 7,500 hectares of mineral claims, of which the principal ones are Indagua, Marta, Escondida, Candelaria, Eduardo, and Chimberos. It is located approximately 1,000 kilometres north of Santiago in Copiapó Province in the III Region of Atacama. It is easily accessible by a 140-kilometre road from Copiapo city centre towards the Andes, of which 30 kilometres are paved. Copiapo is served daily with approximately eight different flights operated by Chilean commercial airlines.
The La Coipa mine operates three open pits: Ladera Ferellon, Coipa Norte and Puren. The Can Can deposit is scheduled to be mined later in the mine life.
Conventional open pit mining methods and equipment are used to mine all ore and waste. Benches are laid out at 10 metre intervals, allowing for berms every two benches. The overall wall slopes are from 45 degrees to 52 degrees.
Mining is carried out with one hydraulic shovel, four front-end loaders, four diesel rotary drills, and thirteen 154-tonne trucks with light beds.
The mine is scheduled to cease production in 2011 if additional reserves are not found.
Mantos de Oro is the operator.
Processing
Ore from Puren is processed in the La Coipa facilities which are located 8 kilometres southwest of the Puren property. The processed material is shipped from Puren to La Coipa by trucks with a capacity of 150 tonnes. The infrastructure requirements of the project are minimal since existing infrastructure at La Coipa will be used.
The La Coipa 17,000 tpd plant commenced operations in October 1991. The plant is beside the Ladera-Farellon pit because it was the original mine.
The processing plant consists of primary crushing, a pre-crushing circuit (semi autogenous ball mill crushing), grinding, leaching, filtering and washing, Merrill-Crowe plant and doré refinery. The Merrill-Crowe metal recovery circuit is better than a carbon-in-pulp system for the high grade silver material. Tailings are filtered to recover excess water as well as residual cyanide and metal credits. A dry tailing disposal system was chosen over a conventional wet tailing impoundment for site specific environmental considerations.
There is a water pump system that collects water from five wells in the Salar de Maricunga. It has enough capacity for the current and foreseeable mine requirements. Endesa, the Chilean Energy Company, supplies power from the "Sistema Interconectado Central" (Central Interconnected System).
The La Coipa plant is a key asset to process satellite deposits from neighbouring concessions.
