Mining Intelligence and News
Peru

La Granja Project

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Categories

Overview

Mine TypeOpen Pit
StagePre-Feasibility
Commodities
  • Copper
Mining Method
  • Truck & Shovel / Loader
Mine Life... Lock
SnapshotThe La Granja project is one of the world’s largest undeveloped copper resources.

La Granja is currently undergoing technical studies and engagement with host communities, local and national governments focused on development of a potential open pit mining operation.

Activities underway
• Work continues to progress community engagement and completion of feasibility study.
• $115 million to be spent in 2025-2027 predominantly on mineral rights, an Environmental Impact Assessment, drilling and other environmental related activities.
• Ongoing engagement with local, regional, and national authorities has indicated strong support for the project at all levels of government.
• Engineering study will focus on developing an updated geological resource and reserve model. As of February 2025, drilling program ~60% complete.
• High-level project layout options, associated infrastructure requirements and logistical routes being developed and assessed.

Owners

SourceSource
CompanyInterestOwnership
Rio Tinto plc 45 % Indirect
First Quantum Minerals Ltd. (operator) 55 % Indirect
In August 2023, Rio Tinto and First Quantum Minerals announced the completion of a transaction that will work to unlock the development of the La Granja project. Under the terms of the transaction, First Quantum Minerals acquired a 55% interest in the project and became the project operator, assuming all key permit obligations.

Deposit type

  • Porphyry
  • Skarn
  • Breccia pipe / Stockwork
  • Vein / narrow vein

Summary:

La Granja is a porphyry copper and associated skarn deposit, with high grade breccias with minor silver, and molybdenum.

La Granja porphyry copper deposit formed due to subduction of the Nazca plate beneath the South American plate in the Andean Cordillera. The district rocks are mainly a thick sequence of volcanic rocks interbedded with occasional sediments which were intruded by the Pomahuanca batholith. Towards the end of the Cretaceous period, La Granja’s small porphyritic felsic to intermediate stocks were intruded.

The deposit has two distinct porphyry clusters, known as Cerro Paja Blanca (CPB) to the east, and Mirador to the west of La Ayraca River. The respective deposits’ lithology and alteration types are similar with their mineralised halos overlapping each other forming “bridge” of skarn material. The deposit is largely circular in shape with a diameter around 2.5 km that decreases with depth. The deposit extents and depth are partially open, with only wide spaced drilling defining current extents.

The La Granja Cu-Mo-Ag-Zn porphyry-breccia complex is hosted by several large, composite, Miocene-age intrusive porphyry stocks of dacitic to dioritic composition with numerous associated hydrothermal breccia phases.

The rocks in the upper levels of the intrusive porphyry and breccia complexes have undergone extensive sericitic (“phyllic”) alteration, consisting of sericite-pyrite development at the expense of almost all original minerals in the host rock. Beneath the pervasive zone of sericitic alteration exists a large zone of potassic alteration in the form of secondary biotite and lesser K-feldspar development. The potassic alteration appears to have been overprinted and destroyed by the sericitic alteration assemblages. Best hypogene copper grades occur in the potassic zone while supergene copper mineralization is almost exclusively hosted within the sericitic zone. Primary copper mineralization consists predominantly of chalcopyrite intergrown with variable amounts of pyrite. Minor amounts of bornite, digenite, tennantite-tetrahedrite, and enargite are also present. The Cu-As sulfide mineralization is believed to have formed from a later phase of more epithermal-like mineralization and is commonly associated with late-stage quartz veins at higher levels in the system. The secondary enriched zone is deeply penetrating and typically consists of “washes” of chalcocite and minor covellite over abundant pyrite crystals. The greater La Granja system of mineralized porphyry, breccias, and associated skarns defined to date covers an area of at least 3.5 km west-east by 2.5 km north-south, still open below 2,000 m from surface.

Recent higher-grade drill intercepts in the Mirador zone suggest a block 2 caving resource potential which may add more than 1.5 Gt at +0.75% Cu at depths from 400 m to 2,000 m from surface. This resource is still open in several directions including at depth.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

Operational metrics

Metrics
Annual production capacity  ....  Subscribe
* According to 2023 study.

Production Costs

Commodity production costs have not been reported.

Heavy Mobile Equipment

Fleet data has not been reported.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Mar 28, 2025
....................... Subscription required ....................... Subscription required Subscription required Mar 28, 2025

Aerial view:

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