Iron carbide synthesis by reaction of iron ore with H-2-CH4 gas mixtures containing traces of sulfur

Particles of hematite ores in a porcelain boat were reacted at 873 similar to 1273 K by H-2-CH4 mixtures having low sulfur activities as based on Fe/FeS equilibrium where metallic iron remained stable. In the tests without sulfur, much free carbon appeared beside metallic iron and iron carbide. The free carbon increased with temperatures. In the tests with sulfur, nearly one hour reaction could convert their particles mostly to iron carbide such as Fe3C, especially favorable in a(S)=0.1 similar to 1.0 at 1173 similar to 1223 K. The conversion yield was sensitive to inlet flow volume ratio H-2/CH4 and ore type, while the authors' previous test in H-2-CO gas mixtures had already indicated their insensitivity.