Chile's Antofagasta Minerals advances toward goal of 900,000t/y copper

Chilean miner Antofagasta Minerals (AMSA) aims to increase its copper production to 900,000t/y from 660,600t/y last year with growth projects at Los Pelambres, Centinela and Zaldívar.

The company is investing US$2.7bn this year in its operations in Chile.

LOS PELAMBRES

To achieve the goal, AMSA is developing the second phase of the planned expansion for Los Pelambres, which will double the capacity of its desalination plant to 800lt/s, incorporate a concentrate pipeline and expand the tailings dam.

Phase 2 is already advancing with preliminary works, AMSA said in a recent statement, and the aim is to extend the useful life of the company’s largest mine until 2051 from 2035 currently.

The project at the operation in Coquimbo region also focuses on continuing to incorporate improvements following the progress made with the complementary infrastructure that included a fourth grinding line.

The higher water availability facilitated by phase 1 contributed to a 19% year-on-year increase in copper production at Los Pelambres in 3Q24 to 92,000t, and a 7% rise in the first nine months of the year to 224,400t, the statement added.

Copper production at Los Pelambres last year was 300,300t. The mine is 60% owned by AMSA and the rest is held by the company’s Japanese partners.

CENTINELA

Another key project is Nueva Centinela, which involves a second concentrator to the operation in Antofagasta region to add 170,000t/y of copper equivalent.

Construction began in April “with more than 5,000 workers and is expected to be completed in 2027,” AMSA said in the statement.

Total copper production at Centinela in the first nine months was 150,700t, down 13% year-on-year due to lower grades. Last year, the operation, which is 70% owned by AMSA and 30% by Marubeni Corporation, produced 242,000t of copper.

ZALDÍVAR

The Zaldívar mine, also in Antofagasta region, has mining and water extraction permits until May 2025 and extending operations beyond then depends on the approval of an environmental impact study for a new project by review agency SEA.

The US$1.2bn initiative seeks to extend the useful life of Zaldívar until 2051 and the main focus is replacing the continental water supply from the Monturaqui-Negrillar-Tilopozo aquifer with seawater or another sustainable source.

It also involves adjusting operations in areas such as the leaching pad and the tailings deposit. If the study is rejected, Zaldívar will begin a closure plan starting next May, AMSA said in an August report.

In 2023, AMSA’s share of copper production from Zaldívar, which is a 50:50 JV with Canada’s Barrick Gold, was 40,500t.

ANTUCOYA

No project has been announced for this AMSA mine, which is also in Antofagasta region. The operation began in 2017 and in the first nine months production was 59,600t, up 6% year-on-year.

GUIDANCE

AMSA expects to achieve production of between 660,000t and 700,000t of copper in 2025, similar to what was forecast for this year. A key aspect of its expansion efforts is to completely replace the consumption of continental water with seawater.

In line with its sustainability strategy, ocean water currently represents 64% of its total water supply. Antucoya and Centinela use only undesalinated seawater while Los Pelambres has its own desalination plant.

The company’s total copper production in the first nine months was 463,700t, down 1.2% year-on-year.