Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Kita-ku, Sapporo, Japan.
Environ Sci Technol. 2011 Jan 15;45(2):821-6. doi: 10.1021/es102910q. Epub 2010 Dec 2.
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.
本文描述了氨还原赤铁矿炼铁的过程，考察了温度对产物的影响。结果表明，在加热过程中，还原过程在 430°C 开始，随着温度的升高，还原机制明显从氨的直接还原（Fe(2)O(3) + 2NH(3) → 2Fe + N(2) + 3H(2)O）转变为通过氨的热分解进行间接还原（2NH(3) → N(2) + 3H(2)，Fe(2)O(3) + 3H(2) → 2Fe + 3H(2)O），温度超过 530°C。在 600 和 700°C 下获得的最终产物是纯金属铁，而在 450°C 下形成的最终产物则是金属铁和氮化铁的混合物。结果表明，氨有可能作为一种还原剂用于无碳炼铁，这种炼铁方法的操作温度远低于传统煤基炼铁的 900°C。
