Name: Candelaria Mining Complex.
Location: Candelaria is located in Atacama – Region III, in Chile.
Controlling Company: The mine is indirectly owned by Lundin Mining and Sumitomo.
Brief Description: The mining complex comprises adjacent Compañía Contractual Minera Candelaria (Minera Candelaria) and Compañía Contractual Minera Ojos del Salado (Minera Ojos del Salado) operations, which produce copper concentrates from openpit and underground mines.
Minera Candelaria is an openpit and underground mine providing copper ore to an on-site concentrator with a capacity of 75 000 t/d.
Minera Ojos del Salado comprises the Santos and Alcaparrosa underground mines. The Santos mine provides copper ore for an on-site 3 800 t/d concentrator and provides an average of 1 400 t/d for the Minera Candelaria concentrator, while all the ore from the Alcaparrosa mine is treated at the Minera Candelaria processing plant.
Brief History: The Candelaria sulphide deposit was discovered by Phelps Dodge Corporation in 1987. A feasibility study was completed in 1990 and, following approval by the Chilean government, construction started in October 1992. Sumitomo acquired a 20% stake in the property in 1992 and production started in early 1995. In 2007, property ownership changed when Freeport-McMoRan acquired Phelps Dodge.
The Santos underground mine has been in production since 1929, with processing taking place at the Pedro Aguirre Cerda (PAC) plant. Phelps Dodge became the sole owner of Minera Ojos del Salado and the Santos mine and PAC plant in 1985. The PAC plant has been expanded several times to its current capacity of 3 800 t/d. Sumitomo acquired its 20% interest in Minera Ojos del Salado in 2005.
In early 1996, production from the Alcaparrosa underground mine started. The PAC plant was shut down from 1998 to 2004, owing to low copper prices.
In November 2014, Lundin acquired Freeport’s interest in the Candelaria Copper Mining Complex.
The Candelaria 2030 project received environmental approval in 2015. Key permits were received during 2016 for the construction of the new Los Diques tailings storage facility. Major civil works began in August 2016 and construction continued until 2017. During 2017, permits were granted to allow the Candelaria underground operations to expand production from 6 000 t/d to 14 000 t/d.
In 2018, the new Los Diques tailings management facility was commissioned and received its first tailings.
Products: Copper, gold and silver.
Geology/Mineralisation: The Candelaria sulphide deposit is located at the boundary between the Coastal Cordillera and the Copiapó Precordillera. The Coastal Cordillera of Chañaral and Copiapó comprises Permian to Lower Cretaceous intrusions within a basement of metasedimentary rocks of Devonian to Carboniferous age. Volcanic, volcaniclastic and marine carbonate rocks represent intra- and back-arc sequences that were deposited during Early to Mid-Cretaceous period.
The Candelaria, Santos and Alcaparrosa mines are located in the district of Punta del Cobre. The polymetallic sulphide deposits are hosted in volcanic rocks of the Punta del Cobre Formation, which are located to the east of the main branches of the Atacama fault zone, a subduction-linked, strike-slip fault system stretching more than 1 000 km along the Chilean coast and active at least since the Jurassic period. The dominant structural elements of the Punta del Cobre area are the north-east-trending Tierra Amarilla Anticlinorium, a south-east-verging, fold-and-thrust system, and a series of north-north-west- to northwest-trending high-angle faults.
The copper/gold sulphide mineralisation found at the Candelaria Copper Mining Complex is generally referred to as iron-oxide copper gold (IOCG) mineralisation. It occurs in breccias, stockwork veinlets, disseminations in andesite, and as an internal tuff unit. There are also some localised controls to mineralisation in the form of faults, breccias, veins and foliation. Candelaria has become an exploration model for Andean-type IOCG deposits that display close relationships to the plutonic complexes and broadly coeval fault systems. Depending on lithology and the structural setting, the polymetallic sulphide mineralisation can occur as veins, hydrothermal breccias, replacement mantos and calcic skarns. The Candelaria IOCG system is situated within the thermal aureole of the Lower Cretaceous magmatic arc plutonic suite in the Candelaria-Punta del Cobre district.
Reserves: Total proven and probable mineral reserves as at June 30, 2018, were estimated at 633.98-million tonnes grading 0.54% copper, 0.13 g/t gold and 1.77 g/t silver.
Resources: Total measured and indicated mineral resources as at June 30, 2018, were estimated at 952.47-million tonnes grading 0.65% copper, 0.15 g/t gold and 2 g/t silver. Inferred resources were estimated at 52.72-million tonnes grading 0.62% copper, 0.12 g/t gold and 1.07 g/t silver.
Mining Method: The mining method at the Minera Candelaria, Santos and Alcaparrosa underground mines is sublevel open stoping.
Major Infrastructure and Equipment:
Minera Candelaria includes:
- the Candelaria openpit with a capacity of 310 000 t/d of rock;
- surface waste dumps located to the north and south-west of the Candelaria openpit;
- a processing plant with a nameplate capacity of 75 000 t/d;
- the Candelaria underground (North Sector), with a current production capacity of 9 000 t/d ramping up to 14 000 t/d by 2021, with the introduction of the South Sector;
- the Candelaria tailings storage facility (TSF), located north-west of the Candelaria openpit;
- the new Los Diques TSF, located to the south-east of the openpit and mine facilities;
- ancillary mine services and administrative buildings, and road accesses;
- the off-site Punta Padrones port, located at Caldera;
- a desalination plant; and
- a pipeline from the Bodega pumpstation to the Candelaria plant site.
Minera Ojos del Salado includes:
- the Alcaparrosa underground mine, with an ore capacity of 4 300 t/d;
- Santos underground mine, with an ore capacity of 5 200 t/d;
- the PAC processing plant, with a capacity of 3 800 t/d; and
- ancillary surface service buildings and road accesses.
Prospects: Ongoing mineral resource expansion exploration has the potential to extend the mine life beyond 2040 and further change the projected copper production profile by replacing low-grade openpit and stockpile mill feed with higher-grade ore extracted from the expanding underground mines and deferring depletion of the low-grade stockpiles. There are also opportunities to increase the throughput capacity of the Candelaria plant through improvement initiatives currently under implementation and modifications to the grinding circuits.
Contact Details:
Tel: +1 416 342 5560
Fax: +1 416 348 0303
Email: info@lundinmining.com
Website https://lundinmining.com