North America’s 10 highest mines

Beijing may dump state metal stocks on overheating markets and is cracking down on speculation as producer inflation hits 12-year high.

Vale was obliged to halt the mine after the workers rejected its initial offer.

The company has a growth initiative in place at each of its core copper operations comprising four operating mines.

Mine in Northern Labrador has started the production at its Reid Brook deposit.

The Department of Energy has identified Class 1 nickel, the type best suited to lithium-ion batteries, as both key vulnerability and key opportunity.

According to Graphene Manufacturing Group and The University of Queensland, graphene aluminum-ion batteries can charge 70 times faster than Li-ion batteries.

The deal will ease concerns over a potential stoppage that would have further tightened global supplies of the metal.

China's major copper smelters reduced output by 4.34% in May from a month earlier to 765,100 tonnes as several of them carried out maintenance.

The world's biggest producer of aluminum rarely sells state metal stockpiles.