The Costa Fuego Copper-Gold Project, a major mining initiative spanning 30 km along Chile’s Panamericana Norte Highway, has released details of its innovative mineral processing circuit in its 2025 Preliminary Feasibility Study (PFS). Developed by Hot Chili Limited, the project integrates four deposits—Productora, Cortadera, Alice, and San Antonio—using a 20 km rope conveyor system to transport ore from Cortadera to a centralized flotation concentrator at Productora. The facility is designed to process 21.7 million tonnes annually (Mt/a) of fresh and oxidized ores, producing copper concentrate, copper cathodes, and molybdenum concentrate, with gold and silver byproducts.
This project represents a significant advancement in copper-gold processing, combining hypersaline leaching technology with a high-capacity concentrator to maximize metal recovery while minimizing environmental impact. Its strategic location near infrastructure and seawater access positions Costa Fuego as a potential leader in sustainable copper production, aligning with global demand for responsibly sourced critical minerals.
Integrated Processing Circuit Design
The Costa Fuego Project features three parallel processing pathways:
- Sulphide Concentrator: A 28 MW gearless SAG mill and twin 19 MW ball mills grind ore to 125 µm P80 for flotation, targeting 87.2% copper recovery. The circuit includes regrinding via IsaMill and produces separate Cu/Mo concentrates.
- Heap Leach: Processes 4 Mt/a of oxide/transition ore through crushing, agglomeration with hypersaline brine (200 g/L NaCl), and stacked leaching, achieving 75% Cu recovery over 240-day cycles.
- Dump Leach: Treats 3.6 Mt/a of low-grade sulphide material with forced aeration, yielding 40% Cu recovery over 730-day cycles.
| Parameter | Value |
|---|---|
| Concentrator Throughput | 21.7 Mt/a (LOM avg) |
| Copper Recovery (Concentrator) | 87.2% |
| Molybdenum Recovery | 71% (88% from Cu/Mo conc.) |
| Heap Leach Production | 12,000 t/yr Cu cathode |
| Rope Conveyor Capacity | 3,640 t/h (29 Mt/a max) |
Key Innovations
The project introduces several technological advancements:
- Hypersaline Leaching: Uses on-site electrodialysis to convert reverse osmosis (RO) brine into leaching solution, eliminating imported salt requirements.
- Adaptive Crushing: Oxide crushing circuit repurposed mid-life to process supplemental sulphide feed, increasing concentrator throughput by 4.7 Mt/a.
- Molybdenum Recovery: Dual-stage CCD washing reduces chloride to <500 ppm in Cu concentrate while enabling 50% Mo grade in final product.
“The 28 MW SAG mill is the largest gearless drive installation globally, and our twin 19 MW ball mills represent the pinnacle of twin-pinion technology,” noted the PFS comminution team. “The circuit is optimized to handle variable ore competence, particularly the hard Cortadera UG ore which limits throughput to 18.7 Mt/a in isolation.”
Environmental and Safety Features
The design emphasizes sustainability through:
- Seawater use for 100% of process water, with RO and electrodialysis minimizing freshwater demand
- Geomembrane-lined heap/dump leach pads with leak detection systems
- Conventional tailings storage with thickened discharge (70% solids)
- Centralized infrastructure reducing trucking emissions
With LOM production of 1.56 Mt copper, 786 koz gold, and 73 Mlb molybdenum, Costa Fuego demonstrates how integrated process design can unlock complex ore bodies. As the PFS concludes, the project moves toward feasibility with potential to set new benchmarks for Chilean copper-gold operations.
Based on filing data from 2024-2025.
Process diagrams from the technical report
Technical report and processing history
The following archived source profiles have been consolidated here to preserve the project’s processing history and study context.
Costa Fuego Copper Project — 2024 Technical Report
Costa Fuego Copper Project — 2024 Technical Report
| Company | Costa Fuego Copper Project |
| Date | 2024 |
| Region | Chile |
| Commodities | Copper, Molybdenum, Gold, Silver |
Executive Summary
This NI 43-101 Technical Report and Preliminary Economic Assessment (PEA) covers the Costa Fuego Copper Project, located in Chile. The project is designed to process both sulphide and oxide material from multiple deposits including Productora, Alice, Cortadera Open Pit, and Cortadera Underground. The processing strategy involves a sulphide concentrator for flotation concentrates of copper and molybdenum, alongside an oxide heap leach circuit producing copper cathode via Solvent Extraction and Electrowinning (SX/EW). A low-grade sulphide dump leach option is also included to maintain consistent metal production through the end of mine life.
The project has a 16-year life of mine with a ramp-up time of one year for both the concentrator and oxide heap leach. The sulphide flotation circuit has an average annual throughput of 21.5 Mt/a, while the oxide heap leach capacity is 3.3 Mt/a. Primary production over the first 14 years averages 95 kt Cu, 49 koz Au, 121 koz Ag, and 3,294 klb Mo. The mineral resource estimate update as of April 2024 does not materially affect the mineral resource inventory that formed the basis of the 2023 PEA.
Processing infrastructure is primarily located near the Productora deposit, with additional facilities at Cortadera. The sulphide concentrator utilizes a SAG and ball mill circuit followed by flotation, while the oxide circuit employs crushing, agglomeration, heap leaching, and SX/EW. The project is currently in the development stage based on the PEA results.
Website: https://www.hotchili.net.au/projects/costa-fuego
Report Date: 2024
Region: Chile
Project Status:
Commodity: Copper, Molybdenum, Gold, Silver
Throughput:
Mine Life:
Mine Type:
Ore type:
Costa Fuego Copper Project — 2023 Technical Report
Costa Fuego Copper Project — 2023 Technical Report
| Company | Costa Fuego Copper Project |
| Date | 2023 |
| Region | Chile |
| Commodities | Copper, Gold, Silver, Molybdenum |
| Mine Type | Open Pit, Underground |
| Throughput | 21.5 Mt/a (Sulphide), 3.3 Mt/a (Oxide) |
| Mine Life | 16 years |
| Status | Development (PEA) |
Executive Summary
The Costa Fuego Copper Project Preliminary Economic Assessment (PEA) outlines a dual-processing strategy designed to handle both sulphide and oxide materials from multiple deposits including Productora, Alice, and Cortadera. The project targets the production of saleable flotation concentrates for copper and molybdenum, alongside copper cathode production via heap leaching for oxide and low-grade sulphide material. The processing facilities are designed to accommodate a ramp-up time of one year with an average annual throughput of 21.5 Mt/a for the sulphide flotation circuit.
Key operational metrics indicate a life-of-mine (LOM) of 16 years with significant metal production averaging 88 kt Cu, 45 koz Au, 121 koz Ag, and 2,999 klb Mo annually. The sulphide concentrator utilizes a conventional SAG and ball mill circuit followed by flotation, while the oxide plant employs crushing, agglomeration, and heap leaching coupled with solvent extraction and electrowinning (SX/EW). The project is currently in the development stage based on the 2023 PEA effective date.
Processing Overview
The sulphide circuit includes primary gyratory crushing, SAG milling, pebble crushing, and ball milling, followed by rougher, scavenger, and cleaner flotation using Jameson cells. The oxide circuit features jaw and cone crushing, drum agglomeration, and three-stage heap leaching. The SX/EW plant treats pregnant leach solution to produce Grade A copper cathodes. Reagent handling and water management systems are designed to support both circuits, including seawater usage and reverse osmosis treatment for low saline water requirements.
Reports
Website: https://www.hotchili.net.au/projects/costa-fuego
Report Date: 2023
Region: Chile
Project Status: Development (PEA)
Commodity: Copper, Gold, Silver, Molybdenum
Throughput: 21.5 Mt/a (Sulphide), 3.3 Mt/a (Oxide)
Mine Life: 16 years
Mine Type: Open Pit, Underground
Ore type:
Productora Copper Project — 2021 Technical Report
Productora Copper Project — 2021 Technical Report
| Company | Hot Chili Limited |
| Date | 2021 |
| Region | Chile |
| Commodities | Copper, Molybdenum |
| Mine Type | Open Pit |
| Throughput | 14 Mtpa (Sulphide), 3.3 Mtpa (Oxide) |
| Annual Production | 75,000 tpa Cu (Concentrate), 10,000 tpa Cu (Cathode), 1,513 tpa Mo |
| Status | Development |
Executive Summary
The Productora Copper Project Technical Report details the processing design for a combined sulphide and oxide open-pit mining operation. The sulphide treatment plant is designed to process 14 Mtpa of ore via a conventional sulphide flotation circuit, producing copper and molybdenum concentrates. The oxide treatment plant processes 3.3 Mtpa of ore through a crushing, agglomeration, and heap leach circuit coupled with a solvent extraction and electrowinning (SX/EW) plant to produce copper cathode.
The sulphide circuit utilizes a SABC comminution design with a primary gyratory crusher, SAG mill, pebble crusher, and ball mills, followed by rougher, cleaner, and recleaner flotation stages. The oxide circuit employs a three-stage crushing and screening process, drum agglomeration with sulphuric acid, and heap leaching on HDPE-lined pads. The SX/EW plant treats pregnant leach solution to produce 10,000 tpa of copper cathode.
The project is currently at the Pre-Feasibility Study (PFS) stage. Key design criteria include a target grind size of 150 µm for the sulphide circuit and a 300-day leach cycle for the oxide circuit. The facility is designed to handle saline water environments, utilizing seawater for process water and implementing specific material selections to mitigate corrosion.
Reports
Entities
Website: https://www.hotchili.net.au/projects/costa-fuego
Report Date: 2021
Region: Chile
Project Status: Development
Commodity: Copper, Molybdenum
Throughput: 14 Mtpa (Sulphide), 3.3 Mtpa (Oxide)
Mine Life:
Mine Type: Open Pit
Ore type:
