The expansion project, which will increase underground Rajo Inca production from 60,000 to 90,000 tons per year, will enter into operations at the end of 2023 and will extend the life of the Salvador division until 2070.

"Until now this division depended on three underground mine pits. The new Salvador will obtain all the mineral contribution from a single pit, with copper grades higher than 40% than the current ones, which will influence in increasing production and productivity," said president of the board of directors of Codelco, Juan Benavide, at the opening.

Optimisation of the project has reduced the initial capital required by 33% since the project was first contemplated in 2014, according to Codelco, reported Mining Journal in January, with a focus on the tailings storage facility, the concentrating and hydrometallurgical plants, and re-use of mining equipment.