Cite this article as:

Saida Shaik, Zhiyuan Chen, Preeti Prakash Sahoo, and Chenna Rao Borra, Kinetics of solid-state reduction of chromite overburden, Int. J. Miner. Metall. Mater., 30(2023), No. 12, pp.2347-2355. https://dx.doi.org/10.1007/s12613-023-2681-y
Saida Shaik, Zhiyuan Chen, Preeti Prakash Sahoo, and Chenna Rao Borra, Kinetics of solid-state reduction of chromite overburden, Int. J. Miner. Metall. Mater., 30(2023), No. 12, pp.2347-2355. https://dx.doi.org/10.1007/s12613-023-2681-y
引用本文 PDF XML SpringerLink

铬铁矿表土的固相还原动力学

摘要: 随着高品位天然铁矿石资源的迅速枯竭和日常生活中对钢铁需求的增加,对低品位铁矿石的需求正在上升。因此,如何有效利用低品位铁矿石一直是冶金工作者重点研究的方向。然而,低品位矿石的直接冶炼会产生的大量渣,消耗大量的能源。一般可以通过先直接还原,然后进行磁选和熔炼的方式来避免这个问题。铬铁矿表土(COB)是铬铁矿选矿过程中产生的矿山废弃物,主要成分为铁、铬、镍(<1wt%),是一种值得利用的低品位铁矿石。本文采用热分析方法对铬铁矿表土制备的自还原球团的固态还原等温和非等温动力学进行了深入研究。结果表明,在900 ~ 1100C 的温度范围内,球团的还原遵循一级自催化反应控制机制。还原反应的自催化性质是由于COB中镍的存在。由动力学结果得到的表观活化能表明,COB与碳之间的固相反应是铁还原的速率决定步骤。

 

Kinetics of solid-state reduction of chromite overburden

Abstract: The demand for alternative low-grade iron ores is on the rise due to the rapid depletion of high-grade natural iron ore resources and the increased need for steel usage in daily life. However, the use of low-grade iron ores is a constant clinical task for industry metallurgists. Direct smelting of low-grade ores consumes a substantial amount of energy due to the large volume of slag generated. This condition can be avoided by direct reduction followed by magnetic separation (to separate the high amount of gangue or refractory and metal parts) and smelting. Chromite overburden (COB) is a mine waste generated in chromite ore processing, and it mainly consists of iron, chromium, and nickel (<1wt%). In the present work, the isothermal and non-isothermal kinetics of the solid-state reduction of self-reduced pellets prepared using low-grade iron ore (COB) were thoroughly investigated via thermal analysis. The results showed that the reduction of pellets followed a first-order autocatalytic reaction control mechanism in the temperature range of 900–1100°C. The autocatalytic nature of the reduction reaction was due to the presence of nickel in the COB. The apparent activation energy obtained from the kinetics results showed that the solid-state reactions between COB and carbon were the rate-determining step in iron oxide reduction.

 

/

返回文章
返回