Patent ID: 8858678

Claim:
A method of making metallic iron nodules with reduced CO and CO 2 emissions comprising the steps of: a. assembling a linear hearth furnace having an entry portion and an exit portion, at least a conversion zone and a fusion zone, and a moving hearth adapted to move reducible iron bearing material through the furnace on contiguous hearth sections; b. assembling a shrouded return substantially free of air ingress extending adjacent to the furnace through which hearth sections can move from adjacent the exit portion to adjacent the entry portion of the linear hearth furnace; c. adjacent the exit portion, transferring the hearth sections from the linear hearth furnace to the shrouded return; d. reducing reducible material in the linear hearth furnace to metallic iron nodules; and e. transporting gases from at least the fusion zone to the shrouded return to heat the hearth sections while in the shrouded return.