Coal slag “provides the best paint/coating surface finish requirement on steel after blasting,” he wrote. Thanks to safety equipment, workers are not at risk, according to the letter.

But he pointed out that OSHA has had information for some time showing unsafe beryllium levels when blasting with slag. “They’ve known about it, they just haven’t enforced it,” he said.

This process is called dustless blasting. It uses a mixture of water and an abrasive such as recycled glass, silica sand, or coal slag. The mixture gets blasted between 60-150 psi.

Camp Hill, Pa.-based Harsco Corp., a leading producer of coal slag and one of two suppliers for Newport News Shipbuilding, responded to OSHA the next month, saying it did not believe that leaving ...

I recently used one to blast four coats of paint off a sheet of diamond-plate steel. It took less than 2 minutes to clean a 1-square-foot area down to bare steel.

The use of coal slag in abrasive blasting at Newport News Shipbuilding is more widespread than originally reported. The slag, a gritty coal-waste byproduct, contains trace amounts of beryllium, a ...

Officials with Opta Minerals Inc., a Canada-based company with a copper slag processing plant in East Baltimore, and for Harsco Corp., based in Camp Hill, Pa., said their slag-based blasting media ...