Actually, the slag floats to the top of molten iron, not steel. The iron produced by the blast furnaces was used in the production of steel. Steel was produced by open hearth furnaces or basic oxygen furnaces. The steel was poured into ingots, which were then rolled into blooms, billets and slabs. These semi-finished products were then rolled into various structural shapes in the mills.
During my employment in the Plant Engineering Department of Bethlehem Steel, I was fortunate to see a blast furnace being tapped. It was fascinating to see the molten iron run into the ladel cars.
That would be my take Dark-Star. The seal is for blast gases (from a furnace presumably) and seals being seals have a tendency to blow...
... so this penguin is having issues with his car so he takes it in for a service. While he's waiting he goes for a walk down to street and passes an ice-cream shop. It's a warm day so what the hell, he gets himself a tasty ice-cream for the walk back to the garage. He gets back and asks the Mechanic what the deal is. "Looks like you've blow a seal" the mechanic states. "Nah" says the penguin "it's just ice-cream".
That would be the place to keep very quiet (Larry is right - big echo potential), keep your ears open, and flatten yourself behind a pillar the instant you heard something.
Holy cow. That's like something out of a videogame where you go "What the heck, an open channel of toxic waste/lava/etc going right through the plant? Who would ever do that?"
I really never thought I'd see something like that in real life. But there it is in living color. Ho. Lee. Cow.
So what exactly does this mean? That there's a safety seal that could blow out instead of something blowing up and you'd better not linger in case that happens?