含铁矿物还原过程的孔隙结构重构行为/机制及其物理化学问题的研究

It is acknowledged that porosity reshaping is of development during the reduction process for iron bearing minerals (sinter, pellet and so on). Due to porosity is a main dynamic condition and key parameter which can contribute the mechanical properties of materials, porosity reshaping will play an important role in reduction process and properties of iron bearing minerals. Therefore, it is essential to theoretically discuss the porosity reshaping of iron bearing minerals in reduction process. The previous studies about the porosity reshaping mainly focus on effects of pore distribution on the metallurgical properties of iron bearing minerals, and insufficient attention have been paid to the porosity reshaping behavior of iron bearing minerals in reduction process. The objective of this project is to study the porosity reshaping behavior. Porosity reshaping behavior will be dynamically investigated by using SEM and Mercury Intrusion Method. Also, porosity reshaping model will be established based on the digital 3D model. Additionally, key factors which can contribute porosity reshaping will be discovered. Finally, the reasonable pore distribution which can balance indirect reduction of BF and metallurgical properties of burden will be pointed out. Through our study, the theory evidence which can be utilized scientifically and rationally about pore control in BF process will be addressed, and it is possible to make full use of the porosity according to the pore control in preparing and reduction process of iron bearing minerals.

烧结矿、球团矿等含铁矿物还原过程始终伴随着孔隙结构重构。由于孔隙率是物理化学反应重要的动力学条件，是影响材料力学性能的关键参数，因此，孔隙重构势必对炉料的还原和性能演变有重要的影响，有必要进行深入探讨。现有研究多侧重于孔隙变化对原料冶金性能的影响，而对含铁矿物还原过程孔隙重构行为关注不足。本立项将从物理化学角度出发，通过扫描电镜动态还原法、压汞法以及图像分析法等研究方法，考察含铁矿物还原过程孔隙重构行为；运用数字岩心三维孔隙重构技术，建立孔隙重构数学模型；同时，研究将揭示影响孔隙重构的主要因素，并指出充分发展炉内间接还原和抑制含铁矿物性能劣化的合理孔隙分布。立项将为炼铁过程科学合理利用孔隙控制提供相应的理论依据，有望实现对含铁矿物制备与还原过程的孔隙控制，继而实现孔隙存在的趋利避害。

烧结矿、球团矿等含铁矿物还原过程始终伴随着孔隙结构重构。由于孔隙率是物理化学反应重要的动力学条件，是影响材料力学性能的关键参数，因此，孔隙重构势必对炉料的还原和性能演变有重要的影响，有必要进行深入探讨。本立项将从物理化学角度出发，通过扫描电镜动态还原法、压汞法以及图像分析法等研究方法，考察含铁矿物还原过程孔隙重构行为；运用数字岩心三维孔隙重构技术，建立孔隙重构数学模型；重构结果表明，球团矿还原初期，孔隙分布比较均匀，形状比较规则，孔径较小；还原过程中，孔隙逐渐聚集，形状不一，孔径逐渐变大。通过对原料粒度、造球工艺（适当增加压实时间）以及矿物组成（添加MgO）的调整可实现孔隙的适度控制。其中，球团（制备条件：-200目粒径矿粉占比85.9%、添加2.0%MgO、生球压实10min）能够具有较适宜的孔隙结构。立项将为炼铁过程科学合理利用孔隙控制提供相应的理论依据，有望实现对含铁矿物制备与还原过程的孔隙控制，继而实现孔隙存在的趋利避害。