Copper checks from continuous caster startup

First fifty tons of a startup cast are returned for remelting because copper contamination causes surface checks before slag layer develops.

Yes, you can sometimes get a little copper contamination before the thing starts oxidizing and forming a little slag layer on the initial startup. That can cause what they call copper checks on the surface. So the first fifty tons you cast maybe just go back to be re-melted. The answer is, on a continuous basis no, on a startup basis yes.