Summary

Deposit type

• Skarn
• Porphyry

Summary:

Las Bambas is located in a belt of Cu (Mo-Au) skarn deposits associated with porphyry type systems situated in south-eastern Peru. This metallogenic belt is controlled by the Andahuaylas-Yauri Batholith of Eocene-Oligocene age, which is emplaced in strongly folded and faulted Mesozoic sedimentary units, with the Ferrobamba Formation (Lower to Upper Cretaceous) being of greatest mineralising importance.

The porphyry style mineralisation occurs in quartz-monzonite to granodiorite rocks. The main economic hypogene minerals are bornite, chalcopyrite and molybdenite, with minor occurrence of supergene copper oxides and carbonates near surface. The intrusive rocks of the batholith in contact with the Ferrobamba limestones gave rise to contact metamorphism and, in certain locations, skarn (garnet, pyroxene and magnetite) bodies with Cu (Mo-Au) mineralisation.

Dimensions
The Las Bambas Mineral Resources comprises three distinct deposits; each have been defined by drilling and estimated:
- Ferrobamba Mineral Resources occupies a footprint which is 2500m N-S and 1800m E-W and over 900m vertically.
- Chalcobamba Mineral Resources occupies a footprint of 2300m N-S and 1300m E-W and 800m vertically.
- Sulfobamba Mineral Resources is 1800m along strike in a NE direction and 850m across strike in a NW direction and 450m deep.
- Ferrobamba Deeps is a vertical extension of Ferrobamba downwards (same XY dimensions), with similar geological features, extending until level 2200RL; the lowest level of the Resource open pit-shell is 3200RL.

Mining Methods

• Truck & Shovel / Loader

Summary:

Mining of the Las Bambas deposits is undertaken by open pit method, which is expected to continue throughout the life of mine. Large scale mining equipment including 300 tonne trucks and 100 tonne electric face shovels are used for material movement.

The mining method selected for the Las Bambas operation is open-cut mining, which enables bulk mining of these large low to moderate grade mineral deposits that are outcropping to sub-cropping. Three deposits, Ferrobamba, Chalcobamba and Sulfobamba are each mined in separate open pits. Mining is by way of conventional truck and shovel operation. This method and selected mining equipment are appropriate for these deposits.

In the pit, the minimum mining width is 70m; the Selective Mining Unit (SMU) has been set at 20m x 20m x 15m.

An extension of Chalcobamba pit in the southwest sector (CBSW) is included in the reserve, after the completion of various assessments and studies, including mine planning, geological confirmation, hydrogeological, geotechnical and metallurgical studies.

The Chalcobamba development, located approximately three kilometres from the existing processing plant at Las Bambas, is crucial to an annual production increase to a range of 350,000 to 400,000 tonnes. The mine began early work with community companies at the Chalcobamba pit in early February 2024, and the plant has received a stable supply of ore from the Chalcobamba pit since the second half of 2024.

Underground options are now under evaluation to extend the Life of Mine, through the inclusion of Ferrobamba Deeps resources, supported by an economically positive Scoping Study which has been executed by Redco Global Peru S.A.C., at the beginning of 2024, under the supervision of Las Bambas key people of the Strategic Planning team.

The Scoping Study confirms the technical and economic viability of the project, with an effective transition from open-pit to underground, applying Block Caving and Sub-level caving methods (UBC methodology applied to assess the most suitable mining method), yielding 860Mt @ 0.37%Cu.

Comminution

Crushers and Mills

Summary:

Metallurgical copper concentration process comprises the following activities: crushing, grinding and flotation.

Las Bambas’ third ball mill was successfully commissioned during the fourth quarter of 2022.

Processing

• Crush & Screen plant
• Flotation
• Dewatering

Summary:

The metallurgical process is a conventional froth flotation concentrator and thickener to produce two separate Cu and Mo concentrates and is appropriate for the style of mineralization.

Metallurgical Copper concentration process comprises the following activities; Crushing, Grinding and Flotation, producing copper and molybdenum concentrates. Copper concentrates contain gold and silver as byproducts.

The ore is crushed and transported on a 5.5-kilometre overland conveyor to a conventional flotation plant where copper concentrate is produced, then to a molybdenum plant for further processing. Concentrate is then transported by truck and rail to the Port of Matarani in the Arequipa region, where it is shipped to customers worldwide.

Water Supply

Summary:

Las Bambas authorised use of water runoff from the Chalhuahuacho River. Water recycling and re-use within the mine eliminates negative impacts with any discharge meeting relevant Peruvian environmental standards.

Water supply is sufficient for site and processing, sourced from the following: rainfall and runoff into Chuspiri dam, groundwater wells, contact waters, recirculating water in the process plant, pump station from Challhuahuacho River off-take structure.

Commodity Production

Operational metrics

Personnel

Job Title	Name	Profile	Ref. Date
Maintenance Planner	Aldo Cabanillas		May 27, 2025
Mine Operations Manager	Rafael Ponce de Leon		May 27, 2025
Operations Superintendent	Abdon Guillen Medina		May 20, 2025
Operations Superintendent	Derly Sandy Vizcarra Arias		May 20, 2025
Plant Manager	Edgar Canta		May 20, 2025
Project Superintendent	Henry Rondon		May 20, 2025