	US 12,221,659 B2
	Method and device for producing direct reduced, carburized metal
Hans E. H. Murray, Djursholm (SE)
Assigned to GREENIRON H2 AB, Sollentuna (SE)
Appl. No. 17/642,890
Filed by GREENIRON H2 AB, Sollentuna (SE)
PCT Filed Sep. 22, 2020, PCT No. PCT/SE2020/050885 § 371(c)(1), (2) Date Mar. 14, 2022, PCT Pub. No. WO2021/061038, PCT Pub. Date Apr. 1, 2021.
Claims priority of application No. 1951070-0 (SE), filed on Sep. 23, 2019.
Prior Publication US 2023/0002841 A1, Jan. 5, 2023
Int. Cl. C21B 13/12 (2006.01); C21B 13/00 (2006.01); C22B 5/12 (2006.01); C23C 8/22 (2006.01)

CPC C21B 13/12 (2013.01) [C21B 13/0073 (2013.01); C22B 5/12 (2013.01); C23C 8/22 (2013.01)]

29 Claims

1. A method for producing direct reduced metal material, comprising the steps:

a) charging metal material to be reduced into a furnace space;

b) evacuating an existing atmosphere from the furnace space so as to achieve a gas pressure of less than 1 bar inside the furnace space;

c) providing heat and hydrogen gas into the furnace space, so that heated hydrogen gas heats the charged metal material to a temperature high enough so that metal oxides present in the metal material are reduced, in turn causing water vapour to be formed, which provision of hydrogen gas is performed so that a pressure of more than 1 bar builds up inside the furnace space; and

d) before an evacuation of gases from the furnace space back to atmospheric pressure, condensing and collecting the water vapour formed in step c in a condenser below the charged metal material; and

e) before an evacuation of gases from the furnace space back to atmospheric pressure, providing a carbon-containing gas to the furnace space, so that the heated and reduced metal material is carburized by said carbon-containing gas.