Permitting and Financing Risks Loom Over Marimaca’s Promising Copper DFS

A Robust Copper Development in Chile

Marimaca Copper Corp. has taken a significant step forward with the release of its Definitive Feasibility Study (DFS) for the Marimaca Oxide Deposit (MOD) located in Chile’s prolific Antofagasta region. The study outlines a 13-year mine life with a steady-state production target of approximately 50,000 tonnes per annum of Grade A copper cathode, positioning the MOD as a compelling development-stage copper project globally.

The project’s initial capital expenditure is estimated at US$587 million, translating to a capital intensity of US$11,700 per tonne of annual copper production capacity. This places Marimaca among the lowest capital cost and intensity copper projects worldwide, a notable achievement given the scale and quality of the deposit.

Financial Strength and Operational Efficiency

Financial metrics from the DFS are robust, with a post-tax net present value (NPV8) of US$709 million and an internal rate of return (IRR) of 31% based on a conservative long-term copper price of US$4.30 per pound. At current market prices around US$5.05 per pound, the project’s post-tax NPV8 rises to over US$1 billion with an IRR nearing 39%, underscoring the project's resilience to price fluctuations.

Operating costs are competitive, with first five years C1 cash costs estimated at US$1.45 per pound and all-in sustaining costs (AISC) at US$1.97 per pound, benchmarking the MOD in the second quartile of global copper producers. The project benefits from a low life-of-mine strip ratio of 0.8, 1 and a simple open-pit mining method, which together contribute to its cost efficiency.

Maiden Ore Reserve and Metallurgical Confidence

The DFS incorporates a maiden Proven and Probable Mineral Reserve of 178.6 million tonnes grading 0.42% total copper, derived from extensive drilling and a dynamic geometallurgical model. Seven phases of metallurgical testing, including large-scale heap leach column tests, underpin recovery assumptions averaging 72% over the life of mine, with higher recoveries in the early years.

Processing will utilize a conventional three-stage crushing circuit followed by agglomeration and dynamic heap leaching, with solvent extraction and electrowinning (SX-EW) to produce premium Grade A copper cathode. The project’s infrastructure design includes oversizing key equipment to allow for future expansions and incorporates a purpose-built water supply system sourcing seawater from the Bay of Mejillones, mitigating freshwater usage risks in the arid Atacama Desert.

Permitting and Financing on Track

Marimaca is progressing well through the permitting process, having submitted its Environmental Impact Statement and engaged in community consultations. Environmental approvals are anticipated by the end of 2025, paving the way for construction commencement in 2026. The company has initiated debt financing discussions, with expressions of interest up to US$500 million, and benefits from strategic equity support from major shareholders including Assore International Holdings and Mitsubishi Corporation.

Early works such as detailed engineering, grade control drilling, and site preparation are planned ahead of the Final Investment Decision (FID). Marimaca also highlights growth opportunities in nearby oxide deposits Pampa Medina and Madrugador, as well as sulphide exploration potential, signaling a broader regional development strategy.

Strategic Outlook

With a strong technical foundation, competitive cost structure, and supportive financing environment, Marimaca’s MOD project is well positioned to advance towards production. The company’s dual listing on the ASX and TSX provides access to diverse capital markets, enhancing its ability to de-risk equity funding. Investors and industry watchers will be keenly observing the permitting milestones and financing outcomes as the project moves closer to becoming a significant copper producer.