>the nitrogen is what's reacting with the iron. Only in a supplementary manner to form a nitride coating as rust proofing - the primary reducing agent is hydro

>the nitrogen is what's reacting with the iron. Only in a supplementary manner to form a nitride coating as rust proofing - the primary reducing agent is hydrogen, forming water. relevant snippet: >>The nitride formation is another key advantage of ADR, as nitriding improves the aqueous corrosion resistance of iron.[29] The nitride passivated the otherwise highly active reduced iron, offering a safety-critical benefit for handling and logistics. Otherwise, for the downstream processing of the reduced material, the porous sponge iron is prone to re-oxidation and strong exothermic reactions with oxygen or moisture due to its high surface-to-volume ratio (typically above 40 vol% porosity[4]). Thus, the sponge iron produced by HyDR must be compacted into hot briquetted iron to reduce the porosity for shipping and handling, which is not necessary with ADR.