Quebrada Blanca copper mine is a two-phased open-pit mine being developed in the Tarapaca Region of Chile, South America.
The first phase (QB1) of the project was commissioned in 1994, while environmental approval for the $4.7bn second phase (QB2) was granted in August 2018. The second phase development is expected to have a mine life of 25 years.
Quebrada Blanca phase two is expected to produce 300,000t of copper-equivalent a year during the first five years of mine life. The new concentrator is anticipated to have a throughput rate of 140,000t/d of copper. It is estimated to produce 7,700t of molybdenum a year.
Teck Resources owns 90% interest and also operates the project, while the remaining 10% is held by Empresa Nacional de Mineria, a state-owned entity.
Quebrada Blanca has produced 23,000t of copper cathode in 2017 and is expected to produce between 20,000t and 24,000t in 2018.
Quebrada Blanca mine geology and mineralisation
Quebrada Blanca project is located approximately 240km south-east of Iquique, the capital city of Tarapaca, in northern Chile.
The deposit is located between middle Eocene and early Oligocene metallogenic belt of northern Chile, majority of which coincides with the Domeyko Fault System. It is located alongside a set of porphyry systems including the Ujina, Rosario and Copaquire (La Profunda) porphyry deposits.
Quebrada Blanca is classified as a complex magmatic and hydrothermal deposit comprising multiple cross-cutting breccia facies and hydrothermal stages.
Quebrada Blanca consists of supergene and hypogene type mineralization.
Quebrada Blanca 2 reserves
The proven and probable reserves at QB2 as of March 2017 were estimated to be 1.26 million tonnes (Mt) grading 0.51% copper and 0.019% molybdenum. The QB2 is estimated to contain 6.42Mt of copper and 237,000t of molybdenum.
Mining at Quebrada Blanca
Conventional open-pit mining with truck and shovel method is being used at Quebrada Blanca. Cathode production at QB1 is proposed to continue until 2019, while the second phase will commence in 2021.
The current mining fleet at QB1 includes 11 Komatsu 730E haul trucks and six Komatsu 830E haul trucks, while an additional 30 Komatsu 930E-4SE trucks will be purchased for QB2 operations.
QB2 will also use conventional methods and conduct mining in five phases. It is expected to have a peak mining rate of 101Mtpa in the third and fourth years of mining.
Ore processing at Quebrada Blanca
Quebrada Blanca currently employs leaching and solvent extraction/electro-winning (SX/EW) methods to produce copper cathodes.
Run-of-mine (ROM) ore from the first phase of QB is crushed in the primary crusher and discharged by conveyor belt to a coarse ore stockpile before feeding to a secondary standard cone crusher. The product is then screened, agglomerated, and stacked before transporting to the dynamic leach pads.
Sulphuric acid is used to leach the ore and the pregnant leach solution (PLS) is forwarded to the SX/EW plant and mixed with organic and diluent to capture the copper and increase the concentration.
Ore at QB2 will be crushed in a single primary crusher of the primary crushing facility and conveyed to the coarse ore stockpile by two overland conveyors. It will be then sent to the concentrator facility, which is equipped with two semi-autogenous grinding (SAG) mills, four ball mills, feed pumps, and cyclone clusters.
The resultant product will undergo pebble crushing and heap leach process followed by flotation system and high-intensity grinding (HIG), and cleaned. It will then be forwarded to the concentrator thickener area.
Molybdenum plant will be installed with molybdenum rougher, three cleaner flotation and regrind equipment, molybdenum concentrate thickener, filter and dryer, and packaging equipment.
Infrastructure facilities for the Quebrada Blanca mine
Most of the existing infrastructure of Quebrada Blanca will be used for the second phase operations. In addition, infrastructure at QB2 will include pipeline system, tailings transport system, and a reclaim water pipeline system to the TMF.
Other infrastructure facilities will also include a 1.25 billion tonne tailings management facility (TMF), a new overhead high-voltage (HV) electric power transmission line, and a desalinated water pipeline system.
A new 28km-long road is proposed to be constructed from the public road A-97B to kilometre 120 of the Pintados private road for accessing the QB2 project. In addition, a 12km section of the Pintados private road will also be improved as part of the mine development.
Power supply for the second phase operations will be provided by AES Gener, under power purchase agreements signed in 2012.
Copper and molybdenum transportation from Quebrada Blanca
Copper and molybdenum final products produced at QB1 are trucked by road to the port of Iquique for ocean shipping.
The bulk copper concentrate produced in the second phase will be shipped from the port site located at Punta Patache, a private port.
E-Mining Technology conducted geotechnical studies for the project, which were updated by Piteau.
Ausenco was engaged for preparing the pre-feasibility study update in phase one of the project and a cost-saving engineering feasibility study report for the phase two.