Which diffusion-based mechanism enabled ancient bloomery furnaces to produce wrought iron from iron ore?

💡 Explanation

In bloomery furnaces, prolonged heating caused carbon migration from the high-carbon iron matrix to the surrounding slag through carburization and decarburization, gradually lowering the iron's carbon content. Therefore carbon migration to slag reduced the iron allowing it to be worked, rather than oxygen reduction, silicon enrichment, or phosphorus depletion, which play secondary roles.

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