Chile-based junior miner Marimaca Copper is looking to garner a substantial foothold in the copper mining sector in Chile, having determined promising prospective operational yields at the Marimaca copper project, with actual copper production to start as early as the first quarter of 2026.

“This has been proven through the announcement last October that the project’s projected resources had doubled over the last six or seven years,” says Marimaca Copper president and CEO Hayden Locke.

The project, which has been developed from a greenfield exploration base, is reported to be a low-risk project, with substantial exploration potential.

The mine has reported measured and indicated resources of about 140-million tonnes grading 0.48% copper for 665 500 t of contained copper, with inferred resources of 83-million tonnes grading 0.39% copper for 323 000 t of contained copper.

Mining will be conducted using an openpit method, relying on a truck-and-shovel method of extraction and haulage, after which ore will be taken to a processing plant for primary beneficiation.

From there, the ore will be moved to a heap leach processing plant, whereby it will be processed to a Grade-A copper cathode using solvent extraction and electrowinning processes.

The company is in the planning and preparation phase of attaining its legal and environmental compliances; the intention is to submit all applications towards the end of 2023.

Locke explains that all baseline data collection – land-use, archaeological and paleontological studies used to underpin the full environmental- and social-impact assessment – has been finalised, which has helped the company understand the key risks of the project.

Water Treatment

The Marimaca copper mine will develop its water reticulation system using recycled water.

Sea water will be supplied to the copper project following its use in cooling systems at an electricity plant in Mejillones, located 25 km from the project and operated by one of Chile’s largest energy suppliers.

This would make the project one of the first mines in the region to not rely on freshwater resources for its operations.

“Our goal is to build an example of a sustainable mine, minimising environmental and social impacts while providing a commodity which is fundamental to the future of our society,” says Locke.

The company’s water strategy, which removes the use of any natural sources of fresh water, is a fundamental example of this goal in action.

He adds that, globally, mining activity accounts for significant use of fresh water, and that such drawing of resources, particularly in arid regions, is a significant social challenge.

In the Beginning

The initial discovery at Marimaca, in the Antofagasta region, was made by Marimaca exploration VP Sergio Rivera.

Locke lauds Rivera, saying that the drilling of the first ten drill holes were all “incredibly successful”.

“The initial discoveries and results have allowed him to then expand the budget with initial investors, and better gauge the magnitude of the discovery,” he says.

Consequently, Rivera made an additional discovery at depth, as well as three satellite discoveries, around the Marimaca copper licence area.

Locke says these discoveries have helped the company to gain better traction with investors, who understand that junior mining is a long-term investment.

“Our investors’ experience and patience have allowed us to continue to move forward despite any volatility in the market,” he concludes.