Patent ID: 8021460

Claim:
A method for producing metallic iron nodules comprising the steps of: providing a hearth material layer comprising at least carbonaceous material on a refractory hearth in a traveling hearth furnace, providing at least one layer of reducible material comprising at least reducing material and reducible iron bearing material arranged in a plurality of discrete compacts over at least a portion of the hearth material layer, heating the reducible material in a drying/heating atmosphere and then in a reducing atmosphere to at least partially reduce the reducible iron bearing material, assembling a shielding entry system to introduce coarse carbonaceous material greater than 6 mesh in particle size into the furnace atmosphere in at least one location such that the temperature of the furnace atmosphere adjacent the at least partially reduced reducible iron bearing material is between about 2200 and 2650° F. (about 1200 and 1450° C.), the shielding entry system adapted to inhibit emission of infrared radiation from the furnace atmosphere and seal the furnace atmosphere from exterior atmosphere while introducing coarse carbonaceous material greater than 6 mesh into an upper portion of the furnace to be distributed over the at least partially reduced reducible iron bearing material, introducing a coarse carbonaceous material of greater than 6 mesh in particle size through the shielding entry system into the upper portion of the furnace, and heating the at least partially reduced reducible iron bearing material in a fusion atmosphere to form from the at least partially reduced reducible iron bearing material one or more metallic iron nodules and slag with the coarse carbonaceous material to assist in fusion and inhibit reoxidation of the reduced material during fusion.