Name of the Mine
Caserones mine.

Location
The Caserones mine is located in Chile’s Atacama region, about 125 km south-east of Copiapó, and about 9 km from the border with Argentina.

Mine Owner/s
Minera Lumina Copper Chile (MLCC) owns the Caserones mine.

Canadian miner Lundin Mining is the operator, holding a 51% interest in MLCC, with JX Metals Corporation holding the remaining 49%.

Brief Description
The Caserones mine produces high-quality copper concentrate, copper cathode and molybdenum concentrate.

Brief History
In 2009, MLCC – which at the time was majority owned by Pan Pacific Copper, a joint venture between JX Nippon Mining & Metals and Mitsui Mining & Smelting – engaged Golder and Associates (since incorporated into WSP) to complete a mineral resource estimate for the Caserones project. The feasibility study was completed in August 2009.

There was no historical mining production from the Caserones deposit prior to the 2009 study.

Construction of the mine began in 2010 and production of refined copper started in March 2013.

JX Nippon Mining & Metals signed an agreement to buy out its partners in November 2020, becoming the sole owner of MLCC.

Lundin Mining completed the acquisition of a majority stake in MLCC in July 2023. A month later, Chile’s environmental regulator fined Caserones the equivalent of $9-million for serious water-use violations, with the Superintendency of the Environment (SMA) noting that noncompliance affected the quality of surface water and groundwater in the Ramadillas river basin.

The SMA said it conducted multiple inspections between 2015 and 2018 after citizen complaints from Colla indigenous communities.

Primary Metals/Minerals
Copper and molybdenum.

Secondary Metals/Minerals
None stated.

Geology and Mineralisation
The Caserones deposit is considered a “classic example” of an Andean copper/molybdenum porphyry deposit.

The basement assemblage is a carboniferous assemblage of metavolcanic and metasedimentary rocks. This assemblage has been intruded by the Caserones Granite in the Upper Carboniferous and the El Colorado Granite in the Permo–Triassic.

The deposit is hosted in a monzogranite within the Caserones Granite and is about 2 km long with a width of about 1.5 km. The oxide and secondary copper zones form a surface-parallel blanket over 1.2 km in diameter with a central ‘core’ of at least 1 km in diameter where thicknesses average 300 m and exceed 400 m in the central part.

The oxide zone forms a cap situated on top of the secondary copper zone in the north-west margin of the deposit area. Flanking the oxide zone and overlying the supergene zone, is a zone of “leached” material. Primary copper mineralisation remains open in all directions.

Reserves
Caserones had a total reserve of 850-million tonnes grading 0.30% copper and 0.014% molybdenum as at December 31, 2022.

Resources
Caserones had a measured and indicated resource of 1.02-billion tonnes grading 0.31% copper and 0.010% molybdenum, and an inferred resource of 121-million tonnes grading 0.25% copper and 0.012% molybdenum as at December 31, 2022.

Type of Mine
Openpit.

Mining Method
Caserones is a traditional openpit truck-and-shovel operation.

Major Infrastructure/Equipment
Several mine roads traverse the property allowing access to different sections of the mine and associated infrastructure.

The mine roads are maintained by contract, with the contractor providing equipment and personnel. However, the mine also has a 300 t/h crusher located on site to produce stemming, road capping and road base materials.

Run-of-mine (RoM) oxide and mixed ores treated using conventional dump heap leaching. Pregnant leach solution from the dump leach is treated at a solvent extraction and electrowinning (SX-EW) plant to produce copper cathodes.

RoM sulphide ore is treated through a conventional primary gyratory crusher and semiautogenous-ball comminution circuit followed by a flotation circuit to produce separate copper and molybdenum concentrates.

The heap leaching and SX-EW processing facilities have been in commercial operation since 2013 while the concentrator reached current capacity in 2014.

The mineral processing facility has support infrastructure including plant offices, a control room, metallurgical laboratory, plant maintenance workshops, reagent storage, and a warehouse for spares and maintenance items.

Caserones operates two tailings storage facilities (TSFs) – El Tambo and La Brea. The El Tambo TSF is a coarse sand tailings facility, while the La Brea TSF receives the fine fraction of the tailings.

The mine has 33 haul trucks, two electric rope shovels, two hydraulic shovels, and two large front-end loaders.

Prospects
Lundin Mining announced in October 2023 that Peter Rockandel would step down at the end of the year and that Jack Lundin, president and former director of the company, would be his successor, rejoining the board on January 1, 2024. He served as president during Lundin’s acquisition of a majority interest in the Caserones mine and the advancement of its portfolio of growth projects.

“During the last two years, under [Rockandel’s] leadership, we have acquired a cornerstone asset in Caserones and successfully moved our corporate headquarters to Vancouver. We have improved operational and financial performance and set the foundation for future growth. None of this would have been possible without [Rockandel’s] tireless efforts. The board deeply thanks him for his contributions,” chairperson Adam Lundin commented at the time.

Lundin has identified and outlined synergies between Caserones and its Candelaria Copper Complex, which are expected to yield initial  savings of $20- to $30-million a year.

In its results for the quarter ended September 30, 2023, Lundin noted that it planned on launching the biggest exploration programme at Caserones since production started in 2013, targeting resource extensions and near-mine discoveries.

Contact Details
Lundin Mining
Tel +1 604 689-7842
Email info@lundinmining.com
 

Sources
Lundin Mining. Website https://lundinmining.com
Lundin Mining. Caserones.
Lundin Mining. NI 43-101 Technical Report on the Caserones Mining Operation Caserones Project (December 31, 2022).
Lundin Mining. Lundin Mining Announces Closing of the Acquisition of Majority Interest in the Caserones Copper-Molybdenum Mine in Chile and Commitments for New $800 Million Term Loan (July 13, 2023).
Lundin Mining. Third Quarter 2023 Results (November 1, 2023).

Mining Technology. Website https://www.mining-technology.com
Mining Technology. Caserones Copper and Molybdenum Deposit, Chile (April 16, 2014).
Mining Technology. JX Nippon to buy out Caserones copper mine in Chile (November 9, 2020).

Mining Weekly. Website https://www.miningweekly.com
Mining Weekly. Chile fines Lundin mine for environmental infractions (August 02, 2023).
Mining Weekly. Lundin Mining CEO Rockandel resigns (October 03, 2023).