Ironmaking with ammonia at low temperature.
This paper describes the reduction of hematite with ammonia for ironmaking, in which the effect of temperature on the products was examined. The results showed that the reduction process began at 430 °C during heating, and with an increase in temperature, the reduction mechanism changed apparently from a direct reduction of ammonia (Fe(2)O(3) + 2NH(3) → 2Fe + N(2) + 3H(2)O) to an indirect reduction via the thermal decomposition of ammonia (2NH(3) → N(2) + 3H(2), Fe(2)O(3) + 3H(2) → 2Fe + 3H(2)O) at temperatures over 530 °C. The final product obtained at 600 and 700 °C was pure metallic iron, in contrast with that formed at 450 °C, that is, a mixture of metallic iron and iron nitride. The results suggest the possibility of using ammonia as a reducing agent for carbonless ironmaking, which is operated at a much lower temperature than 900 °C in conventional coal-based ironmaking.
Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Kita-ku, Sapporo, Japan.
Sou
S
Hosokai
Yoshiaki
Y
Kasiwaya
Kosuke
K
Matsui
Noriyuki
N
Okinaka
Tomohiro
T
Akiyama
D000641:Ammonia / Q000737:chemistry*; D003080:Cold Temperature; D005290:Ferric Compounds / Q000737:chemistry*; D055772:Green Chemistry Technology / Q000379:methods*; D008669:Metallurgy / Q000379:methods*; D010084:Oxidation-Reduction; D014961:X-Ray Diffraction
D005290:Ferric Compounds; C000499:ferric oxide; D000641:Ammonia