[metallurgy]

The flammability limits of hydrogen in air are very wide, from 4% to 75%, and the detonation limits narrower, from 18.3% to 59% at atmospheric pressure. The limits are proportionately wider for a pure oxygen atmosphere. https://www.sciencedirect.com/topics/engineering/hydrogen-explosion

So for the reactions that may be occur inside blast furnace and the other gases around that, how to determine the safe injection of H2 (gas) into blast furnaces of Iron and Steel factory in order to prevent explosive situations..?

The equation is this:
Fe2O3 + 3 H2 = 2 Fe + 3 H2O

So how to prevent the detonation of h2 for the blast furnace gas? What are the limits from the chemistry point of view?