Patent ID: 8690988

Claim:
A method for producing metallic iron nodules comprising the steps of: providing a hearth comprising refractory material; providing reducible mixture above at least a portion of the refractory material, the reducible mixture comprising at least reducing material and reducible iron bearing material; forming a reducible mixture comprising: a quantity of reducible iron bearing material, a quantity of first carbonaceous reducing material of a size less than about 48 mesh of an amount between about 65 percent and about 95 percent of a stoichiometric amount necessary for complete iron reduction of the reducible iron bearing material, and a quantity of second carbonaceous reducing material with an average particle size greater than average particle size of the first carbonaceous reducing material and a size between about 3 mesh and about 48 mesh of an amount between about 20 percent and about 60 percent of a stoichiometric amount of necessary for complete iron reduction of the reducible iron bearing material; where the amount of first carbonaceous reducing material and second carbonaceous reducing material provide total reducing material carbon at least 100 percent of a stoichiometric amount necessary for complete iron reduction of the reducible iron bearing material; thermally treating the reducible mixture in the presence of other carbonaceous material separate from the reducible mixture to form one or more metallic iron nodules.