U.S. miners have stabilized or even increased productivity at both surface and underground coal operations in the past two years, a study released Monday shows.
Vale's Murilo Ferreira has been nominated as Petrobras' next board chairman, while the company still scrambles to deal with the fallout from a vast corruption scandal.
Experts are raising questions about the legitimacy of North Korea's estimated reserves of rare earths, used from computers to cars and defense missiles.