The Group seeks to expand its copper production in Chile and abroad through the development of projects and other potential opportunities. Brownfield development within the Group’s Los Pelambres and Centinela mining districts in Chile remain the primary focus for maximising value while managing risks associated with execution.
Evaluation Projects - 5 years
- Los Pelambres Incremental Expansion
- Twin Metals
- Centinela Second Concentrator
Construction Projects 3-5 years
- Encuentro Oxides
- Molybdenum Plant
- Focus remains on cost control and efficiency throughout the operations
- Focus on higher-return, lower-risk brownfield debottlenecking/expansion projects
- Progress greenfield projects steadily for future development
Evaluation, Construction & Strategy
Centinela Second Concentrator
The second concentrator will be built some 7 km from Centinela’s current concentrator. It is expected to have an ore throughput capacity of approximately 90,000 tonnes per day, with annual production of approximately 140,000 tonnes of copper, 150,000 ounces of gold and 3,000 tonnes of molybdenum. It is currently planned that ore will first be sourced from the Esperanza Sur deposit and, once mining at Encuentro Oxides is completed, ore will also be sourced from Encuentro Sulphides.
This project will allow Centinela to produce 2,400 tonnes of molybdenum per year. The project is being delayed to preserve cash in 2016 and is now expected to be completed in 2017, and will lower Centinela’s unit net cash costs.
The Group continues to evaluate other opportunities in the Centinela Mining District, the most significant of which is Polo Sur. This deposit has a resource of 1.5 billion tonnes at 0.34% copper together with gold and molybdenum, and includes 125.5 million tonnes of copper oxides at 0.40% copper and some additional leachable supergene sulphides. The deposit is approximately 35 km from Centinela and the oxides may act as an additional source of feed for its SX-EW plant in the future.
The Encuentro Oxides deposit is within the Centinela Mining District. It is expected to produce an average of approximately 43,000 tonnes of copper cathode per year over an eight-year period, utilising the existing capacity at Centinela’s SX-EW plant. This will enable the plant to produce at full capacity of 100,000 tonnes per annum for a number of years once the project is complete, helping to offset a decline in production that would otherwise occur due to falling mined grades at Centinela’s existing oxide pits.
Los Pelambres Incremental Expansion
During the year, the Group revised the approach to the incremental expansion of Los Pelambres and decided to split the project into two phases to ease the development of the project and conserve development capital in light of lower commodity prices. This two-phase strategy was approved by the Board during the year and the feasibility study is now underway.
Los Pelambres Mining District – District potential
Given the size of the resource, which at 6.1 billion tonnes is more than three times the quantity of processed ore expected under the existing mine plan, there is significant scope to increase the plant capacity beyond the 205,000 tonnes per day planned for Phase 2 of the incremental expansion project. Such an expansion will require extensive engineering works and permitting as well as the support of local communities and currently no significant evaluation work is planned.
Twin Metals Minnesota Project
Twin Metals Minnesota LLC (“Twin Metals”) is a copper, nickel and platinum group metals (“PGM”) undergroundmining project that holds the Maturi, Maturi Southwest, Birch Lake and Spruce Road copper-nickel-PGM deposits located in north-eastern Minnesota, USA.
The Group completed the acquisition of its project partner in January 2015, bringing Antofagasta’s ownership in the project to 100%.
During 2015, the Group has been undertaking evaluation and optimisation exercises on the pre-feasibility study that was completed in 2014 and has also progressed with geotechnical studies and hydrological fieldwork required to support future environmental reviews and permitting.