Steelmaking method and associated network of plants

21:

• The method as recited in claim 20 wherein the first carbon-based reductant includes coke.

22:

• The method as recited in claim 20 wherein the first carbon-based reductant includes non-fossil carbon reductant.

23:

• The method as recited in claim 20 wherein in step B, the hot blast further including at least one second carbon-based reductant.

24:

• The method as recited in claim 23 wherein the second carbon-based reductant includes non-fossil carbon reductant.

25:

• The method as recited in claim 20 wherein hydrogen produced in a hydrogen production step is added to the H2-rich stream before injection into the blast furnace.

26:

• The method as recited in claim 25 wherein the hydrogen production step is a water decomposition step producing hydrogen and oxygen.

27:

• The method as recited in claim 26 wherein the hot blast includes the oxygen produced in the water decomposition step.

28:

• The method as recited in claim 26 wherein the water decomposition step is an electrolysis reaction.

29:

• The method as recited in claim 28 wherein the electrolysis reaction is powered by renewable energy.

30:

• The method as recited in claim 20 wherein the H2-rich stream is injected into the blast furnace at a temperature from 750° C. to 1100° C.

31:

• The method as recited in claim 20 wherein from 200 Nm3 to 700 Nm3 of the hydrogen are injected into the blast furnace per ton of hot metal to be produced.

32:

• The method as recited in claim 30 wherein more than 50% in volume of the hydrogen injected into the blast furnace is hydrogen extracted from the blast furnace top-gas.

33:

• The method as recited in claim 20 wherein hydrogen extracted from a reduction top gas of a direct reduced iron production step is added to the H2-rich stream before injection into the blast furnace.

35:

• The ironmaking production plant as recited in claim 34 further comprising a hydrogen production plant and an hydrogen gas line allowing mixing of the produced hydrogen in the hydrogen production plant with the H2-rich stream before injection into the blast furnace through the second injector.

36:

• The ironmaking production plant as recited in claim 35 wherein the hydrogen production plant is a water decomposition plant producing hydrogen and oxygen.

37:

• The ironmaking production plant as recited in claim 36 further comprising an oxygen gas line allowing injection of the produced oxygen with the hot blast before injection into the blast furnace through the first injector.