lol. you're right. It is pig iron, my mistake. Explains why I couldn't even find it on google. I was trying to remember for the life of me what he had said exactly. I've been slowing down lately while playing trying to understand everything. When I first got civ4 I just went thru it like gangbusters and didn't stop to smell the roses.......or pig iron.
http://en.wikipedia.org/wiki/Pig_iron
Pig iron is raw iron, the immediate product of smelting iron ore with coke and limestone in a blast furnace. Pig iron has a very high carbon content, typically 3.5%, which makes it very brittle and not useful directly as a material except for limited applications.
If anyone can answer my other questions, that'd be great too, but here is a breif explaination on what pig iron is.