The over-reduction of Fe₂O₃ in iron-bearing tailing during magnetization roasting is one of the main obstacles for the application of magnetization roasting with coal reductants. It is of great importance to explore suitable reductants for the magnetization roasting to recover iron form the tailing. In this paper, we developed pyrite as a reductant for the magnetization roasting and it was used to recover iron form iron-bearing tailing. Here, we show that addition of pyrite during the magnetization roasting process remarkably hindered the over-reduction of Fe₂O₃ to FeO and promoted the formation of Fe₃O₄. The experimental results confirmed, magnetization roasting with pyrite as reductant, the concentrate with an iron grade of 61.03% and iron recovery of 94.70% were obtained, under the roasting temperature of 800℃, pyrite addition of 1.0 g, tailing addition of 16.0 g and roasting time of 30.0 min, nitrogen flow rate of 100.0 mL/min, magnetic field intensity of 130.0 kA/m and magnetic separation time of 10.0 min. In addition, a possible reaction mechanism between FeS₂ and Fe₂O₃ was proposed based on thermodynamic, thermogravimetric, X-ray diffraction analysis and experimental validation. The results of this research confirmed that pyrite is an effective and environment-friendly reductant for the magnetization roasting to recover iron from iron-bearing tailing.

磁化焙烧过程中含铁尾矿中Fe ₂ O ₃的过度还原是煤还原剂磁化焙烧应用的主要障碍之一。探索合适的还原剂用于磁化焙烧从尾矿中回收铁具有重要意义。在本文中，我们开发了黄铁矿作为磁化焙烧的还原剂，并将其用于从含铁尾矿中回收铁。在这里，我们表明在磁化焙烧过程中添加黄铁矿显着阻碍了 Fe ₂ O ₃过度还原为 FeO 并促进了 Fe ₃ O _4的形成. 实验结果证实，以黄铁矿为还原剂进行磁化焙烧，得到铁品位61.03%、铁回收率94.70%的精矿，焙烧温度800℃，黄铁矿添加量1.0g，尾矿添加量16.0g，焙烧时间30.0 min，氮气流速100.0 mL/min，磁场强度130.0 kA/m，磁选时间10.0 min。此外，基于热力学、热重、X射线衍射分析和实验验证，提出了FeS ₂与Fe ₂ O _{3之间可能的反应机理。}本研究结果证实，黄铁矿是一种有效、环保的磁化焙烧从含铁尾矿中回收铁的还原剂。