Summary

Deposit type

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

Summary:

volcanic column, hosted by a sub-vertical, cylindrical-shape diorite porphyry (600-700 m in diameter). The intrusion has undergone significant meteoric processes at the top of the column, generating an upper level known as the leached cap, underlain by mixed and copper enriched zones which overlie the main hypogene portion of the deposit. The gold-only leached cap is free of copper, which is concentrated in the supergene enriched horizons.

Around 80 % of the orebody is hypogene and the remaining 20 % is oxide or supergene, notwithstanding that most of the supergene and oxide ore has already been mined and the remnant ore is primary sulphide in nature.

The Cerro Corona porphyry system is strongly altered, ranging from propylitic in the distal zones to predominantly argillic in the central zone. Varying proportions of clay-sericite are encountered and potassic alteration intensity increases with depth.

The entire system contains a strongly developed stockwork system. The stockwo

Mining

• Truck & Shovel / Loader

Summary:

c units. Haul roads have 10 % of maximum gradient configuration. All material requires drill and blast with varying powder factors according to rock hardness using 200 mm diameter production BHs.

The operations quarry is being mined to provide limestone for the TSF construction. A proportion of the clay waste removed from the pit is also used for this purpose.

All operation and maintenance of mining equipment is completed by the mining contractor.

The new mining contractor has flexibility relating to its mining fleet and is committed to mobilising a fleet of 45 t trucks as the material movement rate increases.

Mining fleet and machinery requirements
Load and haul activities are carried out by 11 x 40 t trucks, 13 x 45 t trucks, 23 x 55 t trucks and 5 excavators with a bucket capacity varying between 4.8 and 6 m³.

Comminution

Crushers and Mills

Summary:

Lokotrack LT-140E as a primary crusher and MMD Sizer as a primary/secondary crusher that receives coarse material with a top size of 1 m. Fine ore from the mine (-0.23 m) is fed to the hoppers through a belt conveyor (each line includes a 300 t hopper). From the hopper, a 1.07 m apron feeder sends the ore to a MMD Sizer crusher that reduces the ore size from 0.15 m to 0.10 m. The crushed ore is then conveyed by a 1.4m belt feeder to the 1.07 m overland conveyor.

The grinding area includes a 24’ x 14.5’ SAG mill that reduces the ore size to 1” particle and 20’ x 34’ ball mill working in a closed circuit with a 26” hydro cyclone nest that reduces the ore particle size to 80 % passing the 140-160 um mesh range. The pulp is discharged into a conditioning tank which is fed to the flotation plant. A cone crusher was implemented in this area to process pebbles from the SAG mill with the product fed back to the ball mill.

Plant upgrades and development
Replacement of Abon Sizers with MMD Sizers
Replacement of both Abon Sizers with upgraded MMD Sizers with higher hardness rock crushing capacity was completed during 2021 and 2022.

SAG mill grates configuration change
During 2019 and 2020, Cerro Corona engaged Fluor to review the set-up and performance of the comminution circuit. One of the recommendations made to increase capacity of the circuit was to increase the aperture and open area of the SAG mill discharge grates. Following trials undertaken in 2020 and 2021, all the discharge grates were replaced with larger apertures of 45-50 x 34 mm, targeting a throughput increase of approximately 4 t/hr.

Beneficiation

• Gravity separation
• Centrifugal concentrator
• Crush & Screen plant
• Flotation
• Dewatering
• Filter press

Summary:

hr or 6.7 Mt/a with an availability of 91.32 %.

The flotation plant includes a rougher stage of seven 160 m³ Outokumpu flotation cells to produce a concentrate recovering 85 %-90 % of the copper and 65 %-70 % of the gold. The rougher flotation tails are thickened in a 36.6 m diameter thickener to a density of 45-52 % solids and then piped to the TSF.

The concentrate is processed through two stages of cleaning cells of different size to deliver a concentrate of 20 % copper and 30 g/t gold. The cleaning circuit also includes four regrind mills and five 50 m³ Outokumpu cleanerscavenger flotation cells. The cleaner tails from this circuit are piped to the TSF.

A Falcon gravity concentrator is included in the circuit for the recovery gold in iron from the rougher concentrate, which is then sent to the final concentrate thickener. The tailings from the gravimetric process continues the normal process to the cleaning flotation circuit.

The final concentrate is thickened in a 16 m diameter thickener to 63 % solids and then pumped to a fully automatic Metso filter. Concentrate with 7-9 % moisture is stored in a dome with a 5,000 t capacity before loading into 30 t trucks that transport the concentrate in seven vehicle convoys over 380 km to Salaverry port. The concentrate is loaded in ships for export to copper smelters in Japan and Germany.

Several plant improvement or optimisation projects were recently completed or remain in progress.

Gravity circuit reconfiguration
The existing Falcon gravity concentrator was recently reconfigured for incorporation into the concentrate regrind circuit, recirculating load instead of being fed rougher concentrate. This provides an opportunity for multiple passes of coarse gold to be presented to the concentrator due to recirculation of gold through the regrind circuit hydrocyclones, with the aim to increase gravity recovery.

Replacement of Abon Sizers with MMD Sizers
Replacement of both Abon Sizers with upgraded MMD Sizers with higher hardness rock crushing capacity was completed during 2021 and 2022.

SAG mill grates configuration change During 2019 and 2020, Cerro Corona engaged Fluor to review the set-up and performance of the comminution circuit. One of the recommendations made to increase capacity of the circuit was to increase the aperture and open area of the SAG mill discharge grates.

Following trials undertaken in 2020 and 2021, all the discharge grates were replaced with larger apertures of 45-50 x 34 mm, targeting a throughput increase of approximately 4 t/hr.

Water Supply

Summary:

e season to control risk, thus oscillating the volume of clear water in the TSF between 1.5 and 2.4 Mm³ to cover the demand of the operation and ensure the operation of the installed pumping systems.

Rainwater from the mine and other flows are the main sources of water supply for Cerro Corona which is stored in the TSF. Water required for the process plant is sourced from the TSF and returned to the TSF together with the tailings.

Ground and runoff water from the Cerro Corona open pit is pumped to the TSF and is included in the global water balance. When required, a portion of the water stored in the TSF is pumped to a water treatment plant and discharged to the Tingo River in accordance with national discharge regulations and the Water Discharge Licence.

Water supply for the Cerro Corona camp comes from pit dewatering and the UCB drainage system as well as from PPC-1 pumping. A portion of the water pumped from the pit is treated on-site and sent to the camp. Some of this water is also sent to the Hualgayoc basin.

Commodity Production

Operational metrics

Personnel

Job Title	Name	Profile	Ref. Date
Exploration Manager	Juan Carlos Sarmiento Arias		Aug 7, 2024
VP Operations	Ronald Diaz Vásquez		Aug 7, 2024