铁矿粉聚团流态化还原结构调控与模拟优化

To avoid defluidization during gas-based fluidized bed reduction, this project presents a novel process to reduce iron ore fines by agglomerate fluidization. To solve the existing key problems during agglomerate reduction in fluidized bed, the formation and evolution of agglomerates are carefully studied, and the critical conditions for stable fluidized bed reduction of agglomerates are clarified. The regulation of agglomerate structure will be established, which can promote the permeability of agglomerates but inhibit the increase of size, to conduct reduction by agglomerate fluidization quickly and steadily. Further, based on the experimental results, the local structure-effect relation model will be created, which can precisely simulate and predict the flow and reaction behaviors of agglomerates combined with the two-fluid model, thereby instructing the design, scale-up and optimization of industrial reactor. Eventually, a novel method for efficient reduction of iron ore fines with new theory will be obtained, which can provide scientific support for the industrial application of agglomerate reduction in fluidized bed.

为了避免流态化气基还原炼铁中出现失流，项目提出了聚团流态化还原的创新工艺。针对铁矿粉聚团流态化还原中存在的关键问题，项目拟通过研究揭示聚团的形成和演变规律，探明稳定聚团流态化还原的临界条件，建立聚团微观结构和尺寸的调控机制，从而实现聚团快速、稳定地流态化还原。并进一步采用基于结构的局部构效关系模型与双流体模型相结合的方法，准确模拟预测流化床内聚团的流动反应行为，从而指导实际反应器的设计、放大和优化。最终形成铁矿粉高效还原的新理论新方法，为聚团流态化还原的工业应用提供重要的科学理论支撑。

为了避免流态化气基还原炼铁中出现失流，项目提出了聚团流态化还原的创新工艺。针对铁矿粉聚团流态化还原中存在的聚团结构调控和还原过程优化等关键科学问题，项目采用实验研究与理论分析相结合的方法进行了突破：(1)通过实验研究和力平衡模型分析揭示了铁矿粉高温气基流态化还原中聚团的形成和演变规律，探明了稳定聚团流态化还原的临界条件；通过混合-制粒的改性方法建立了聚团微观结构和尺寸的调控机制，提高了聚团还原速率，抑制了聚团长大，从而实现了铁矿粉快速、稳定地聚团流态化还原；(2)建立了基于聚团结构-反应-粘结的构效关系模型，定量评估了流化床内聚团的流动反应行为，为还原过程优化和工业应用提供了重要的基础理论支撑和参考。