US 12,227,820 B2
Method and device for producing direct reduced metal
Hans Murray, Djursholm (SE)
Assigned to GREENIRON H2 AB, Sollentuna (SE)
Appl. No. 17/599,501
Filed by GREENIRON H2 AB, Sollentuna (SE)
PCT Filed Mar. 31, 2020, PCT No. PCT/SE2020/050335
§ 371(c)(1), (2) Date Sep. 28, 2021,
PCT Pub. No. WO2020/204795, PCT Pub. Date Oct. 8, 2020.
Claims priority of application No. 1950403-4 (SE), filed on Apr. 1, 2019.
Prior Publication US 2022/0119914 A1, Apr. 21, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. C22B 5/12 (2006.01); C21B 13/00 (2006.01); C21B 13/12 (2006.01)
CPC C22B 5/12 (2013.01) [C21B 13/004 (2013.01); C21B 13/0073 (2013.01); C21B 13/12 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for batchwise production of direct reduced metal material in a furnace that is part of a closed system, the furnace including a heated furnace space, the method comprising the steps:
a) charging metal material to be reduced into the furnace space;
b) evacuating an existing atmosphere from the furnace space so as to achieve an underpressure inside the furnace space;
c) providing, in a main heating step, heat and hydrogen gas to the furnace space, so that heated hydrogen gas heats the charged metal material and reduces metal oxides present in the metal material, in turn causing water vapor to be formed; and
d) condensing and collecting the water vapor formed in step c in a condenser below the charged metal material;
wherein steps c and d are performed at least until a hydrogen atmosphere overpressure has been reached inside the furnace space, and
wherein no hydrogen gas is evacuated from the furnace space during steps c and d until the overpressure has been reached.