Antofagasta and Marubeni have decided to move ahead with the expansion of the Centinela copper mine in the Antofagasta Region in Chile with an investment of $4.4bn.

The copper expansion project entails the establishment of a new 95 kilotonnes per day (ktpd) concentrator plant situated approximately 7km south of the existing facility. The primary goal is to double the production capacities for copper concentrate.

Presently, the existing concentrator processes ore from the Esperanza deposit and Esperanza Sur deposits, while the upcoming plant will handle ore from the Esperanza Sur deposit and the Encuentro deposit to generate copper concentrate.

Upon the conclusion of the expansion, the Centinela copper mine is anticipated to have an approximate annual increase of 140,000 tonnes per annum (tpa) in copper production. This will place it among the top 15 copper mines globally in terms of output, said Marubeni.

Besides, the expansion project will increase the gold production by 130,000oz per annum and molybdenum production by 3,500tpa.

The expected mine life following the expansion will be 36 years, driven by Centinela’s substantial ore reserve, amounting to two billion tonnes.

Marubeni stated: “As a result of this increase, the share of equity copper volume attributable to Marubeni’s interest is set to increase by approximately 40 thousand tons annually. In addition, the production of gold, a by-product of the copper mining, is anticipated to make Centinela one of the leading gold producers in Chile.”

The Centinela mine’s second concentrator project has obtained all necessary permits from Chilean authorities, allowing it to advance to the construction phase. The project is scheduled for a three-year construction period, and crucial construction activities are set to commence shortly.

First production from the expansion project is expected in 2027, said Antofagasta which has a 70% stake in the Centinela copper mine, while its Japanese partner Marubeni holds the remaining 30% stake.

Antofagasta CEO Iván Arriagada said: “This brownfield expansion project is expected to deliver attractive returns in excess of our cost of capital at a wide range of commodity prices. We are leveraging more than 20-years of operational experience and understanding of Centinela’s ores, utilising existing infrastructure and building on long-established relationships within our local communities.”