“Converting iron to steel also involves the introduction of various other metals, manganese, chromium, nickel, etc; to create alloys with various desirable characteristics. For this to occur, the metals have to be liquified.”
And Carbon. First and foremost Steel is an alloy of iron and carbon.
Came here for this.
Maybe they can make low temp iron, but unless they're going to make Lodge frying pans, they need to add carbon to iron to make steel.
True, but iron has too much carbon in it. The carbon precipitates as flakes of carbon when the iron solidifies. These weaken the iron and make it brittle. This excess carbon is removed in order to make much stronger and more ductile (bendable) steel.
You are correct sir. Cole is not just for heat, it is the carbon source, as you said.