Vale maintains 'positive' outlook for iron-ore, nickel prices

"Our outlook for iron ore remains positive, given the recovery of the global economy," Vale said after iron-ore prices plunged in late November, hit by over-supply concerns and weaker steel demand. They have since recouped some of those losses.

The company, once the world's top producer of the steel ingredient, said its fourth-quarter net profit nearly doubled to $5.4-billion. The growth was mainly due to the impact of a reclassification of cumulative foreign exchange gains, the company said.

The financial gains were partially offset by higher expenses related to the Brumadinho dam disaster, such as an additional provision of $1.7-billion related to upstream dams.

Vale's earnings sustained an impact from last year's iron ore price drop, but nickel has been on the rise for the past few years and the miner is betting that demand for the metal used in electric vehicles will continue to grow.