At peak levels, the world would need to dig up 3.3 gigatons of earth every year to obtain the necessary metals.

The Stolberg plant largely supplies European battery producers with lead.

The Imbabura provincial court said a 2014 environmental license and other permissions given for the Llurimagua project do not comply with proper parameters.

Freeport is keeping an eye out for deals but is focused on its own projects, Adkerson said.

Pre-feasibility activities for the private land Phase I of the Copper World project in Arizona are well-advanced, says Hudbay.

The deal would be the second-largest mining acquisition in Canada.

Output from Codelco fell 14.8% year on year to 105,400 tonnes.

The company owns the Julimar nickel project, one of the biggest nickel sulphide finds in recent years.