The firm is also trying to halve use of cobalt in batteries from around 20% by raising the proportion of nickel, and it will start researching on development of nearly cobalt-free batteries.
The miner has also scrapped its 2017 dividend after full-year core earnings fell by more than a third because of a ban on unprocessed mineral exports in Tanzania.
The U.S. Forest Service signed off on exploration for copper, gold and other minerals on 900 federal acres that lie just outside the Mount St. Helens National Volcanic Monument in Southwest Washington.
