I've seen here and other places that the dross on the top of molten alloy is antimony, tin and trace metals. I've seen in other places where it is crud that gets onto the metal before it is melted.
How can the alloy separate after it is thoroughly mixed. In my understanding, compounds can separate, but an alloy cannot, as it is chemically changed when blended, like bronze, for example. Any one out there with a metallurgy background?