The preventive measure seeks to protect trucks to and from the mine amid fresh protests against alleged pollution.

Phase one was completed 15 months ahead of schedule and for $50 million less than originally expected.

It was a year to forget for many of the base metals with copper, aluminium, zinc and lead closing out 2019 little changed from year-start levels.

The move will help South32 expand its portfolio in North America.

The miner, which operates the Mutamba project in a joint venture with Rio Tinto, says permit is valid to April 2044.

Co-products will initially be sold to ceramics industry customers in Portugal and Spain.

The precious metals miner said that 3,904 were permanent positions, while 1,366 were contractors.

Chile's Codelco has a new funding strategy that includes issuing debt and selling non-structural assets.