The Tilden mine, which primarily supplies the company's own AK Steel facilities in Ohio and Michigan, was idled in mid-April, with a restart previously expected in July. It will now open this month in response to a faster improvement in steel demand from AK Steel's clients, particularly in the automotive sector.

The company will also be resuming construction of its Hot-Briquetted Iron (HBI) plant in Toledo, Ohio.

"The demand for our steel, iron ore, and metallics products has recovered dramatically over the past month, and in light of this, we are restarting Toledo and Tilden sooner than we originally expected," said president and chief executive Lourenco Goncalves.

"We suspended these operations in a way that allowed us to restart as easily and efficiently as possible, and that is what we will do. Our footprint is well situated to capitalize on the rapidly increasing demand from the automotive sector, which is occurring faster than our most aggressive expectations."