[jordanb]

Main contaminate in iron ore is oxygen. The refining process is mostly removing stuff yes.

"Steel" is defined as carbon content between .02% and 2%. If the metal has less than that it's wrought iron. If it had more than that it's cast iron.

So steel is a range of carbon contents that gives particularly useful properties.

Historically the lower end of that was higher but with that addition of other alloys we have "low carbon steels" that behave like steel with very little carbon.