AK Steel Corp.’s joint venture in the iron ore business announced Tuesday plans to build a pellet plant in Reynolds, Ind.

Butler County’s AK Steel in the fall of 2011 formed a joint venture to make iron ore concentrate. The company is called Magnetation LLC, and is a partnership between AK Steel and Magnetation Inc. of Nashwauk, Minn.

Construction on the more than $300 million iron ore pellet plant is anticipated to start in the first quarter of next year, the company said. The pellet plant is expected to start operations at the end of 2014 or the beginning of 2015, and employ about 100 to 120 people.

Once running, Magnetation will transport iron ore concentrate from its mineral recovery operations in Northern Minnesota to the new plant in Reynolds. The concentrate will be converted into high-quality iron ore pellets for use by AK Steel.

The project has been moving forward as fast as possible, AK Steel said.

“The construction of Magnetation’s new pellet plant supports our objective to become approximately 50 percent self-sufficient in iron ore pellets by the year 2015 — about a year ahead of schedule. This will help insulate AK Steel from volatile swings in market prices for iron ore, a key raw material in the steelmaking process,” said AK Steel spokesman Mike Wallner.

AK Steel is headquartered in West Chester Twp. and operates several steel mills, including Middletown Works.