Chile Copper Mine To Reduce Water Extraction From Atacama Salt Flats

SANTIAGO, Chile

The world’s largest copper mine, Escondida, announced 4 February that it has reconsidered plans to continue water extractions from the vulnerable Atacama salt flats in Chile, and advance deployment of desalination technology.

While rich in copper and lithium deposits, Chile’s Atacama region presents severe operating challenges for extraction companies. In 2019 copper production in Chile dropped by 44,000 tons compared to 2018, attributable to water scarcity, falling ore grades at many deposits, and aging infrastructure. Escondida’s 2019 production was down more 4 percent over 2018.

BHP Billiton, with a 57 percent interest in the mine, has decided to withdraw applications for water permits to extract up to 428 liters per second from underground aquifers. The plan is to switch to using desalinated water by 2030. Already fulfilling 40 percent of the mine’s water requirements, desalinated water comes from a recently completed coastal desal plant and is transported 3200 meters above sea level.

A statement from BHP said that the “decision advances by 10 years (BHP’s) commitment to stop extracting high Andean water for Escondida.” It had previously said it would shut off the freshwater taps in 2030. The statement also indicated that the decision had considered conversations with indigenous communities in the region.

Conversely, Antofagasta’s Zaldívar copper mine must also renew its water extraction permits but it has no back-up plan.

The current license allows 500 liters per second to be pumped through 2025. Antofagasta is requesting a renewal of the license at 213 liters per second through 2029. If the extension is not granted, operations will have to cease. If the extension is granted, the mine will probably shut down in 2029 in any event.

For its part, the big lithium mining companies, SQM and Albemarle are seeking additional water resources. The Atacama salt flat supply more than one-third of the global supply of lithium, a key ingredient in the batteries that power the soaring global market for electric vehicles.

Albemarle has filed for permission to monitor underground aquifer flows, underscoring the importance of water in mining operations of the metal that is widely used in batteries.

Further, increasing involvement of indigenous communities has also raised the sensitivity of end users to the social and environmental impact of mining operations and it has been reported that auto manufacturers are demanding greater transparency with respect to both environmental impact as well as social conditions in the region.

This demand seems to be triggered by the Chilean government’s efforts to protect natural resources. In December, the courts supported indigenous communities and rejected SQM’s environmental remediation plan. The judges are reported to have warned the company that the plan was based on “junk science” with a “high level of scientific uncertainty” about the Atacama water table.

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