I worked a summer stint at Birmingham Steel down in Birmingham, AL during college. Birmingham Steel recycles junk iron and steel and makes it into rebar. Their smelting schedule was fairly regular and if I got to work just before 7am, they would have just drawn off a load of slag from the electric-arc furnace.

Their technique for disposing of the slag was to back a regular dump truck up to the slag removal port of the furnace and pour the molten slag into it. Then some brave soul would drive the dump truck around to the rear of the plant and dump it out in a slag pit. Keep in mind that slag is molten, burning, flaming waste. Now imagine watching a dump truck drive by, a 40 foot high pillar of flame pouring out of the back of it, and a lone steel plant worker with balls of steel in the driver's seat.

I dunno if OSHA approved of this ..