How a 3,000-degree pile of slag and a downpour created a wild night in Middletown

When hot slag comes in contact with moisture the result sounds “like a bomb going off,” said the safety chairman for the IAM Local Lodge 1943 that represents steelworkers at AK Steel.

Some speculated a bomb exploded on Feb. 24 when three loud booms were heard coming from the area of the Middletown steel plant. People in Middletown and as far away as Franklin reported hearing the booms around 11:20 p.m. on Feb. 24. Middletown police dispatchers received numerous calls from concerned citizens, and some area residents wrote on social media that their homes shookfor the first time.

ExploreREAD MORE: Source of loud booms in Middletown identified

The source of the noise was the main topic for several days on local Facebook pages.

Jim Gomia, safety chairman for the union, lives behind Middletown High School about four miles from where the booms originated off Oxford State Road. When he heard the noises, Gomia realized it wasn’t thunder.

“Very pronounced” is how he described the noise.

Slag is a byproduct of the steelmaking process and can be extremely hot, up to 3,000 degrees, Gomia said.

Slag was being transported from AK Steel to a slag pit just south of Oxford State Road when it was dumped in rain water that caused “a louder than usual noise,” Douglas Huffnagel from Stein, the company that was moving the slag, wrote in an e-mail.

Huffnagel said no one was injured and no equipment was damaged during the incident. For more than 60 years, Stein Inc. has been providing slag processing and steel mill services, according to its website.

Middletown’s John A. Peterson, a retired researcher at Armco, said that when slag is introduced to water, the water turns to a vapor state “so darn fast,” it creates “explosions without explosive materials.”

The Middletown area received about two inches of rain on Friday and Saturday, according to the National Weather Service in Wilmington. Gomia said the slag pit could have been nearly flooded on Saturday night.

Gomia said the union is conducting an investigation to determine what possibly caused the booms. But he said the union is considering ways to reduce the risk of injury in the slag removal and dumping process. He said when slag is removed from the steel plant, it’s transported in a slag hauler to a large area across Oxford State Road. When the slag, which can be liquid or in a lava form, is poured into a pit, and in this case, a pool full of rain water, the vapor gets trapped.

When that happens, “booms” occur, he said.

He said one of the dangers of such explosions is the possibility that slag can fall and crack windows in the truck cabs.

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