US 12,084,730 B2
Methods and systems for increasing the carbon content of direct reduced iron in a reduction furnace
Keith Marshall Bastow-Cox, Charlotte, NC (US); Todd Michael Astoria, Harrisburg, NC (US); and Gregory Darel Hughes, Charlotte, NC (US)
Assigned to Midrex Technologies, Inc., Charlotte, NC (US)
Filed by Midrex Technologies, Inc., Charlotte, NC (US)
Filed on Mar. 23, 2021, as Appl. No. 17/209,506.
Claims priority of provisional application 62/993,771, filed on Mar. 24, 2020.
Prior Publication US 2021/0301358 A1, Sep. 30, 2021
Int. Cl. C21B 13/00 (2006.01); C21B 13/02 (2006.01)
CPC C21B 13/0073 (2013.01) [C21B 13/02 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A direct reduced shaft furnace comprising:
a reduction zone;
a transition zone separate and after the reduction zone, wherein the transition zone has multiple vertically stacked tiers, and each tier is configured to receive a separate flow of a mixed carburized gas stream, wherein the mixed carburized gas stream comprises a mixture of a carbon monoxide-rich gas stream and a hydrocarbon-rich gas stream; and
a cooling zone located below the transition zone, wherein the direct reduced shaft furnace is configured to expose reduced iron partially or completely to each of the mixed carburizing gas streams and increase the carbon content of resulting direct reduced iron of the direct reduced shaft furnace to greater than about 4.5 wt. %.