How is charcoal used in the making of steel? Or is used in foundries?
How are the biggest users of lump charcoal in the U.S?

Coke is generally used to make steel as it is cheaper and denser than
charcoal, otherwise I think they are interchangable. My guess is,
outdor cooking is the largest user of lump charcoal, with comercial
cooking of specialty foods such as Woody's Barbecue and  Sonny's
Barbecue second.   Neil