Sentence:  Miravich closes his eyes and remembers his days as a <WSD>slagger</WSD>. When a mold is full, a <WSD>slagger</WSD> moves in with his tool, a techmological marvel othereise known as a board slightly larger than a two-by-four. He leans out over the track and skims slag off the top of the boiling steel, risking what is called “catching a flyer,” which occurs when hot metal explodes out of the mold, spraying everyone in the vicinity. 
Meaning of the word marked with <WSD> tags:  One who works with slag.