Source: Vicuña Corp. (2026)
Website: https://www.lundinmining.com/our-portfolio/projects/vicuna-district/
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Throughput | 175,000 | tpd | Stage 1 sulphide mill nameplate (three grinding lines) |
| Mill Power | 26 | MW | Per SAG mill (three installed), gearless drive; ball mills 22 MW each |
| Target Grind Size | 130 | μm P80 | Flotation feed size from grinding circuit |
| Head Grade | Not specified | Head grade not provided in Section 17 | |
| Recovery % | 86.3 | % | Overall copper recovery for Stage 1 sulphide mill |
| Processing Capacity | 175,000 | tpd | Same as throughput; Stage 1 |
| Energy Consumption | Not specified | kWh/t | Not provided in Section 17; estimated from mill power not given |
| Water Consumption | Not specified | m³/t | Not provided in Section 17 |
| Operating Hours | Not specified | hours/day | Not provided; assumed continuous 24/7 |
Overview
The Vicuña Project, a major copper-gold development straddling the Argentina-Chile border, is operated by Lundin Mining Corporation and Vicuña Corp. The 2026 Preliminary Economic Assessment (PEA) outlines a phased three-stage processing strategy designed to optimize recovery from the Josemaria and Filo del Sol deposits. The Stage 1 Sulphide Mill employs conventional copper-gold flotation to process sulphide mineralization from Josemaria, featuring primary crushing, grinding, flotation, regrind, and concentrate dewatering. Stage 2 adds a district leaching circuit for oxide mineralization from Filo del Sol, utilizing SX-EW for copper and Merrill-Crowe for gold and silver recovery, along with a SART plant for cyanide regeneration. Stage 3 expands sulphide processing capacity to incorporate deeper Filo del Sol sulphides via a phased approach that includes overland conveying and additional grinding and flotation lines. The significance of this staged development lies in its ability to match processing capacity to evolving resource profiles, achieving an overall copper recovery of 86.3% in Stage 1 and targeting saleable concentrate grades averaging 25.4% copper. The process flowsheet integrates advanced comminution with gearless mill drives, high-rate thickening, and robust tailings management to ensure efficient, sustainable operations.
Key Process Stages
- Stage 1: Primary Crushing and Coarse Material Handling – Two 1,525 mm x 2,260 mm Metso Mk III gyratory crushers (540 t surge pockets each) reduce Run-of-Mine ore to a nominal F80 of 120 mm. Crushed material is conveyed via a 500 m system to an 80,000 t live capacity covered stockpile with 10 hours of live storage per grinding line. Reclaim tunnels with belt feeders feed three SAG mill circuits.
- Stage 2: Comminution – Three parallel grinding lines each consist of a 12.2 m diameter x 7.9 m EGL SAG mill (26 MW gearless drive) and an 8.3 m x 13.7 m EGL ball mill (22 MW gearless drive). SAG mills operate at 15% ball charge (138 mm media) to achieve a T80 of 2,500 µm. Cyclone classification targets a flotation feed P80 of 130 µm at 56% solids. Overall nameplate throughput is 175,000 t/d.
- Stage 3: Rougher & Pyrite Rougher Flotation – Cyclone overflow enters two parallel flotation lines, each with seven 630 m³ copper rougher cells and two 630 m³ pyrite rougher cells. Rougher residence time is ~25 minutes, achieving an average rougher concentrate grade of 2.29% Cu at 95.5% stage recovery (14% mass pull). Pyrite rougher flotation uses a stronger collector to produce low-sulphur tailings.
- Stage 4: Regrind & Cleaning Circuit – Rougher concentrate is pre-cleaned in three 630 m³ cells (3.8% Cu, 97.8% recovery) before entering the regrind circuit with three 3,356 kW vertical stirred mills in closed circuit with cyclones. Target regrind product size is 25–30 µm. The cleaning circuit comprises first cleaners (five 200 m³ cells), cleaner-scavengers (three 300 m³ cells), and second cleaners. Final concentrate averages 23.5–28.9% Cu.
- Stage 5: Concentrate Dewatering and Tailings Thickening – Final concentrate is thickened in a 30 m diameter high-rate thickener to 63% solids, then filtered to 10.9–12% moisture for truck shipment via rotainers. Rougher tailings are thickened in two 100 m diameter high-rate thickeners to 58% solids for low-sulphur TSF. Cleaner tailings (pyrite concentrate, pre-cleaner tails) thicken in a 70 m diameter unit to 48% solids for lined high-sulphur TSF.
Additional Interesting Data and Summary
Beyond Stage 1, the Vicuña Project’s Stage 2 (District Leaching) processes 90,000 t/d at the Filo site, with 60,000 t/d of copper-gold blend material on an on/off heap leach pad and 30,000 t/d of gold oxide on a dedicated ROM pad. The on/off pad operates nine months per year due to winter constraints. Blend material undergoes primary crushing (Metso Mk III gyratory), grizzly screening, acid scrubbing, and secondary crushing (MP1250 cone crusher) to P80 38 mm before stacking on a 550 x 965 m pad (7.5 m height). Leaching uses raffinate at 10 L/m²/h with drip emitters; a 52-day active leach cycle followed by 9-day rinse. SX-EW recovers copper from PLS, while Merrill-Crowe and gold refining recover precious metals. A SART plant regenerates cyanide and precipitates copper. Stage 3 (Sulphide Expansion) introduces Filo del Sol sulphides in two phases: Stage 3A adds primary crushing at Filo and an overland conveyor to Josemaria, modifying existing flotation circuits; Stage 3B expands grinding and flotation capacity with additional mills and cells. Concentrate transport and desalinated water supply infrastructure are included later. Environmental considerations include lined tailings storage facilities for high-sulphur tailings, process water ponds for recycling, and flocculant-assisted thickening to minimize water consumption. The economic impact is significant: Stage 1 alone targets 86.3% copper recovery with concentrate grades up to 28.9% Cu. Sustainability initiatives include variable speed mill drives for energy efficiency, SART for cyanide recovery, and staged construction to align capital deployment with resource development. The future outlook includes potential expansion to higher-grade Filo sulphide zones, with the PEA providing a robust foundation for feasibility studies. The Vicuña Project’s three-stage approach exemplifies adaptive mineral processing design for complex polymetallic deposits, ensuring maximum value extraction while maintaining operational flexibility.
Key Processes: Flotation, Heap Leaching, Cyanidation, Gravity Separation, SAG Mill, Ball Mill, Crushing
Target Commodities: Gold, Silver, Copper, Zinc, Lead
Technical report and processing history
The following archived source profiles have been consolidated here to preserve the project’s processing history and study context.
Vicuña Project — 2026 Technical Report
Vicuña Project — 2026 Technical Report
| Company | Vicuña Corp. |
| Date | March 2026 |
| Region | Argentina, Chile |
| Commodities | Copper, Gold, Silver |
| Mine Type | Open Pit |
| Throughput | 175,000 – 293,000 t/d |
| Mine Life | ~75 years |
| Status | Development (PEA) |
Executive Summary
The Vicuña Project is a greenfield mining development located across the Argentina–Chile border, encompassing the Josemaria and Filo del Sol deposits. The 2026 Preliminary Economic Assessment (PEA) outlines a three-stage processing strategy designed to handle evolving mineral resource profiles. Stage 1 focuses on the Josemaria sulphide deposit with a conventional copper–gold flotation circuit. Stage 2 introduces district leaching for Filo del Sol oxide mineralization using SX-EW and Merrill-Crowe circuits. Stage 3 expands sulphide processing capacity to include Filo del Sol sulphides, integrating them with the existing Josemaria infrastructure.
The project utilizes open-pit mining methods with a combined nameplate throughput reaching 293,000 t/d in Stage 3. Key commodities include copper, gold, and silver. Infrastructure includes two open pits, multiple stockpiles, waste rock storage facilities, heap leach pads, and tailings storage facilities. Water supply will transition from groundwater to a desalination plant pipeline from the Chilean coast in Stage 3. The project is a joint venture between BHP and Lundin Mining, with an option held by Mitsui & Co. Limited.
Processing involves a mix of comminution, flotation, and leaching technologies. Sulphide ores are processed via SAG and ball milling followed by flotation, while oxide ores undergo heap leaching with acid or cyanide solutions. Concentrate post-treatment includes a reductive roasting plant to manage high-arsenic content. The project aims to produce copper concentrate, copper cathodes, and gold–silver doré, with logistics involving trucking initially and a concentrate pipeline in Stage 3.
Reports
- reports/2026_Vicuna_Project
Entities
- entities/Vicuna_Project
- entities/Josemaria_Mine
- entities/Filo_del_Sol_Mine
- entities/Vicuna_Corp
Website: https://www.lundinmining.com/our-portfolio/projects/vicuna-district/
Report Date: March 2026
Region: Argentina, Chile
Project Status: Development (PEA)
Commodity: Copper, Gold, Silver
Throughput: 175,000 – 293,000 t/d
Mine Life: ~75 years
Mine Type: Open Pit
Ore type:
Josemaría Copper-Gold Technical Report (PFS) — 2018
The 2018 PFS defines a 150,000 tpd sulphide ore processing plant designed to produce copper concentrate using HPGR comminution and conventional flotation.
Report context
This technical report presents the results of a Pre-Feasibility Study (PFS) for the Josemaría copper-gold project, dated December 2018. The process facilities are designed to treat a nominal rate of 150,000 tpd of sulphide ore and produce copper concentrate. The process design is based on existing technologies and the largest available and proven equipment sizes.
Processing route
Comminution Circuit Selection
Ausenco undertook a comminution circuit review study for the Josemaría project as part of the PFS. This review included benchmarking the Josemaría ore against other operations, evaluating the previous comminution circuit design, providing a high-level design for SABC (semi-autogenous mill, ball mill, and pebble crushing) and HPGR-B plants, and updating the capital and operating cost estimates.
A conservative approach was adopted for sizing the HPGRs due to a limited number of HPGR laboratory and/or pilot trials completed and the absence of parameters obtained therefrom such as specific throughput rates (M-dot) and recycle rates. An HPGR motor power of 6,800 kW was considered to ensure that the installed power is sufficient to achieve nominal throughput rate.
The SABC circuit option is an established technological approach to comminution and generally results in smaller physical footprints than HPGR-based circuits. The capital cost estimate showed that installation of an SABC circuit resulted in 15% lower Capex than the HPGR-B circuit. However, the SABC circuit required higher energy and steel media consumption and the operating cost estimated for the HPGR-B circuit was 27% lower than that for the SABC circuit. The ore characteristics, net present cost (NPC) calculations and benchmarking against similar ores strongly support the use of HPGR technology over the life of the Josemaría project. The cumulative NPC was calculated for a 20-year period using an 8% discount rate.
Crushing and Screening
The crushing circuit will consist of two parallel trains of identical primary gyratory crushers (1,000 kW installed power), treating a total of 8,333 tph (dry). ROM material will be delivered to the primary crushers by mine trucks into a single dump pocket with a 500-t live capacity. The primary crusher will receive ROM (F100 of 1,200 mm) and reduce it to a P80 of 137 mm. The primary crusher will discharge into a 500-t live capacity surge pocket where a variable speed apron feeder will deliver ore to the coarse ore stockpile feed conveyor.
Dual reclaim tunnel systems will house a total of six reclaim apron feeders (three per train) that draw ore from the coarse ore stockpile (454,000 wet t) to two coarse ore reclaim conveyors. The coarse ore stockpile will have a total live capacity of 12 hours of mill feed at the nominal feed rate (91,000 wet t). Material will be reclaimed at an average rate of 3,676 tph (dry) per train.
There will be four secondary cone crushers (933 kW installed power), each operating in an independent line. The oversize (P100 = 365 mm) will be reduced to a product with a P80 of 41 mm. An allocation of space for two additional crushers will allow for possible future expansion.
Tertiary crushing will be performed by four independent HPGR lines (6,800 kW installed power). The HPGRs will be in closed circuit with wet screens, with the downstream fine ore screens providing a control on the particle size to the grinding circuit (F80 = 3.8 mm). Oversize (> 6 mm) from these screens will return to the HPGR surge bin.
Grinding
There will be four independent grinding lines, each consisting of a fine ore surge bin, two reclaim feeders, two screens, a pump box and cyclone feed pump, a cyclone cluster and a ball mill (7.9 m diameter x 12.5 m effective grinding length with 19,000 kW installed power). Cyclone overflow (P80 = 130 µm) will be sampled and analyzed for size and metal content as it passes to two banks of the rougher scavenger flotation circuit. Each grinding line will have a single (duty only) variable speed cyclone feed pump.
Flotation
The flotation circuit is designed to receive feed material grading 0.29% Cu and 0.21 g/t Au over the LOM. Nominal copper recovery to the flotation concentrate is 86.4%, with a gold recovery of 70.9%. Nominal copper concentrate grade is expected to be 25.1% Cu with 14.5 g/t Au.
Flotation comprises rougher scavenger flotation, regrinding of the rougher concentrate and three stages of cleaner flotation to produce a final copper concentrate. Rougher scavenger flotation will consist of two parallel lines of nine 630 m³ forced air tank flotation cells fed at a density of 35% w/w solids. The concentrate from the first two cells of each row, of higher copper grade, will be diverted directly to cleaner flotation, bypassing the regrind stage. The concentrate from the remaining seven cells will require regrind prior to further upgrading.
The regrind section will consist of three vertical stirred regrind mills (11,220 kW installed power), where size reduction to a P80 of 25 µm will be achieved in closed circuit with hydrocyclones.
The first cleaner flotation section will consist of six 300 m³ forced air tank flotation cells. The tailings from the first cleaner flotation will feed the cleaner scavenger flotation section consisting of seven 630 m³ forced air tank flotation cells. The second cleaner flotation section will consist of six 70 m³ forced air tank flotation cells. The third cleaner section will consist of six 30 m³ forced air tank flotation cells.
Copper flotation will be promoted using Potassium Amyl Xanthate (PAX), Sascol 95 and Matcol TC-123 collectors with Methyl Isobutyl Carbinol (MIBC) added as a frother. Lime will be used for pH modification, as required.
Concentrate Dewatering
The final copper concentrate will be thickened with flocculant to 65% solids in a high-rate thickener (35-m diameter). An agitated tank will have capacity to store six hours production of thickened concentrate ahead of the filtration stage. One pressure filter (61 plates, 2.5 m by 2.5 m plates) will reduce moisture content of the concentrate to approximately 9% for shipment.
Tailings Management
Flotation tailings will represent approximately 98% of the total plant feed tonnage. Tailings will initially be thickened in two high rate thickeners (85 m diameter) to approximately 62% solids and pumped to the TSF. The thickener overflow will be recycled to the process water system. The overall facility has no discharge to the surrounding environment other than water evaporation to the atmosphere.
Key reported parameters
| Area | Description | Rate | Basis |
|---|---|---|---|
| Process General | Plant Design Capacity | 54.75 Mt/year | Design |
| Process General | Plant Design Capacity | 150 ktpd | Design |
| Process General | Primary Crushing Availability | 75% | Ausenco benchmark |
| Process General | Secondary Crushing Availability | 85% | Ausenco benchmark |
| Process General | HPGR availability | 90% | Ausenco benchmark |
| Process General | Grinding and Flotation availability | 90% | Ausenco benchmark |
| Process General | Coarse Ore Stockpile Live volume | 12 hours | Ausenco benchmark |
| Ore Characteristics | Specific gravity | 2.77 | SGS Phase II testwork |
| Ore Characteristics | JK SMC test parameters, A x b | 32.1 | SGS Phase II testwork (25th percentile) |
| Ore Characteristics | Bond rod mill work index | 13.3 kWh/t | SGS Phase II testwork (75th percentile) |
| Ore Characteristics | Bond ball mill work index | 14.7 kWh/t | SGS Phase II testwork (75th percentile) |
| Ore Characteristics | Bond abrasion index | 0.187 g | SGS Phase II testwork (75th percentile) |
| Grinding | Target P80 | 130 µm | SGS Phase II testwork |
| Flotation | Average copper head grade | 0.29% | Mine plan |
| Flotation | Mass pull to final concentrate | 1.39% new feed | SGS Phase II testwork |
| Flotation | Copper recovery | 86.4% | Nominal design |
| Flotation | Gold recovery | 70.9% | Nominal design |
| Flotation | Copper concentrate grade | 25.1% Cu | Nominal design |
| Flotation | Gold in concentrate | 14.5 g/t Au | Nominal design |
| Regrind | Target P80 | 25 µm | SGS Phase II testwork |
| Concentrate Filter | Final moisture content | 9% | Ausenco benchmark |
| Major Requirements | Total installed power | 188 MW | Design |
| Major Requirements | Peak demand power | 150 MW | Design |
| Major Requirements | Process make-up water | 23,584,398 m³/a | Design |
| Major Requirements | Steel grinding media | 4,271 t/a | Design |
| Major Requirements | Concentrate tonnage | 761,025 t/a | Design |
Project website: https://ngexminerals.com/
Technical qualifications
The HPGR sizing adopted a conservative approach due to a limited number of HPGR laboratory and/or pilot trials completed, and the absence of parameters such as specific throughput rates (M-dot) and recycle rates. Process design criteria and equipment sizing are mainly based on the Phase II testwork completed by SGS, which included comminution and flotation tests on both composite and variability samples suitable for PFS level. Simplified flotation tests conducted by ALS, Kamloops in the late stage of the PFS showed potential to reduce the flotation circuit size and simplify reagent schemes relative to earlier testwork, and further testwork is recommended to evaluate the simplified flotation circuit and reagent schemes in the next phase of study.
Source: Josemaría Copper-Gold Technical Report (PFS), December 2018, Section 17 Recovery Methods.
Filo del Sol — 2019 Technical Report
The pre-feasibility study for the Filo del Sol project outlines a processing route based on heap leaching with copper solvent extraction and electrowinning, supported by extensive metallurgical testwork completed through 2018.
Report context
This NI 43-101 technical report was prepared for Filo Mining Corp. with an effective date of 13 January 2019. The report presents the results of a pre-feasibility study for the Filo del Sol project, a copper-gold-silver deposit located on the border between Chile and Argentina. The processing and metallurgical sections are documented in Chapter 13 (Mineral Processing and Metallurgical Testing) and Chapter 17 (Recovery Methods) of the original report.
Processing route
Process design overview
The proposed recovery methods described in the pre-feasibility study comprise a heap leaching operation followed by copper solvent extraction and electrowinning to produce copper cathode. The process description is provided in Section 17.1 and 17.2 of the report, with design criteria presented in Section 17.3.
Metallurgical testwork programs
Metallurgical testing was conducted in multiple phases. Phase IV testwork was completed by SGS Minerals (Lakefield) in 2018 and is documented in Section 13.2. Section 13.3 presents the results of the 2018 metallurgical program, including testwork outcomes for gold, silver, and copper recovery. Section 13.4 discusses alternative leaching processes that were evaluated but not selected for the base case design. Section 13.5 provides a preliminary evaluation of potential process improvements. Section 13.6 details miscellaneous test programs that were completed to support process design assumptions.
Metal recovery estimates
Metal recovery estimates are presented in Section 13.7 of the report. These estimates were derived from the metallurgical testwork programs and form the basis for process design performance assumptions in the pre-feasibility study.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Processing method | Heap leaching with SX-EW | Proposed design (Section 17.1, 17.2) |
| Primary metal products | Copper cathode | Proposed design |
| Metallurgical testwork | Phase IV completed by SGS Minerals (Lakefield), 2018 | Historical testwork (Section 13.2) |
| Alternative processes evaluated | Yes – documented in Section 13.4 | Testwork comparison |
| Process improvements evaluated | Yes – preliminary evaluation in Section 13.5 | Testwork assessment |
| Miscellaneous test programs | Yes – documented in Section 13.6 | Historical testwork |
| Metal recovery estimates | Provided in Section 13.7 | Derived from testwork |
| Design criteria | Presented in Section 17.3 | Proposed design basis |
Project website: https://en.wikipedia.org/wiki/Filo_del_Sol
Technical qualifications
The metallurgical testwork programs were conducted by SGS Minerals (Lakefield) in 2018, with results documented in Section 13.2 and 13.3. The recovery methods described in Chapter 17 represent the proposed design for the pre-feasibility study. Alternative leaching processes and potential process improvements were evaluated but do not necessarily show final design selections. The miscellaneous test programs in Section 13.6 provide supplementary data supporting the metallurgical assumptions. Design criteria in Section 17.3 are based on the testwork outcomes and engineering analysis completed for the pre-feasibility study.
Source: NI 43-101 Technical Report, Pre-feasibility Study for the Filo del Sol Project, effective 13 January 2019, Sections 13 and 17.
