Steel Mills

AK Steel Ashland Works Furnace Shutdown

July 31, 2014

AK Steel has shut down the blast furnace at Ashland Works for the second time this year. A “hearth chill” incident occurred last week (described as excess water in the furnace) according to AK Steel officials during the company’s earnings conference call Wednesday, and further maintenance was anticipated.

In an email to SMU, Mike Wallner, General Manager, Communications and Public Relations wrote:

“AK Steel recently experienced an unplanned stoppage at its Ashland Works (KY) blast furnace. The company is working to remedy the situation and minimize any potential impact on its customers.”

If the outage is because of a hearth chill it could be a serious problem for AK Steel. A research article by Ron van Oudenallen, Egenolf van Stein Callenfels, et al., describes a hearth chill as follows:

“A chilled blast furnace is one of the most serious disruptions in an integrated steel plant, as it might take weeks to bring the furnace back to normal production. During a hearth chill, liquids cannot be tapped since the temperature in the lower part of the furnace has become too low. The connection between the taphole and tuyeres has been lost, primarily owing to solidification of slag. This solidified slag obstructs the flow of liquids into the hearth. If a chill is very severe, the remaining hot metal in the hearth may start solidifying as well. Blast Furnace chills can be minor (connection lost, but sufficient heat in the hearth) to very severe (connection lost and all hearth contents solidified).”