Ironmaking with ammonia at low temperature

Environ Sci Technol. 2011 Jan 15;45(2):821-6. doi: 10.1021/es102910q. Epub 2010 Dec 2.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonia / chemistry*
  • Cold Temperature*
  • Ferric Compounds / chemistry*
  • Green Chemistry Technology / methods*
  • Metallurgy / methods*
  • Oxidation-Reduction
  • X-Ray Diffraction

Substances

  • Ferric Compounds
  • ferric oxide
  • Ammonia