复合共生铁矿流态化气基还原过程附碳效应及其动力学耦合调控粘结失流的研究

Direct reduction technology based on gas-solid fluidized-bed is an important way to utilize low grade and complex paragenetic iron ores. This project focuses on resolving the defluidization problem by the method of surface modification of carbon deposition during fluidized-bed reduction of fine ores. The aims are to investigate the physico-chemistry behavior of conversion and migration of element C during carbon deposition, as well as the evolution law of surface microstructure of ore powders, and thus to master the control conditions for surface morphology of iron microcrystals. In order to reveal the mechanism of particle agglomeration and its inhibition in fluidization reduction ironmaking, the structure-function relationship between surface micro-properties and defluidization characteristics of particles will be elucidated. Furthermore, The coupling correlation characteristics of reaction kinetics for carbon deposition and consumption are analyzed by investigating the multiphase reaction kinetics in the Fe-C-O system, and thus the synergistic mechanism and process optimization model of carbon deposition modification and iron ore reduction are obtained. The reasonable amount of carbon deposition is determined in different reaction conditions. As a result, on the basis of surface structure regulation and kinetic coupling, the technical principles and methods for prevention of particle agglomeration by surface modification will be established, which will provide theoretical foundation and technical surport for the solution to defluidization during ironmaking by fluidized-bed process.

流态化气基直接还原技术是解决我国低品位、复合共生铁矿资源利用的重要途径。本项目针对铁矿粉流态化还原过程的粘结失流，旨在利用附碳表面改性的方法解决矿粉颗粒粘结问题，重点研究析碳过程中碳素转化、迁移的物理化学行为，以及铁矿颗粒表面微观结构的演变规律，掌握表面铁微晶形态的控制条件，阐明颗粒表面微观性质与粘结特性之间的构效关系，揭示流化床气体还原炼铁过程中颗粒间的粘结和防粘结机理；通过研究附碳条件下Fe-C-O体系的多相反应动力学行为，解析附碳过程碳沉积/消耗反应动力学耦合关联特性，获得附碳和矿石还原之间的协同机制及过程优化模型，确定不同反应条件下的合理附碳量。基于表面结构调控与反应过程耦合，建立表面改性抑制颗粒粘结的的技术原理和方法，为解决流态化气体还原炼铁的粘结失流问题提供理论基础及技术支持。

流态化气基直接还原技术是解决我国低品位、复合共生铁矿资源利用的重要途径。本项目针对铁矿粉流态化还原过程的粘结失流，旨在利用附碳表面改性的方法解决矿粉颗粒粘结问题，重点研究析碳过程中碳素转化、迁移的物理化学行为，以及铁矿颗粒表面微观结构的演变规律，掌握表面铁微晶形态的控制条件，阐明颗粒表面微观性质与粘结特性之间的构效关系，揭示流化床气体还原炼铁过程中颗粒间的粘结和防粘结机理；通过研究附碳条件下Fe-C-O体系的多相反应动力学行为，解析附碳过程碳沉积/消耗反应动力学耦合关联特性，获得附碳和矿石还原之间的协同机制及过程优化模型，确定不同反应条件下的合理附碳量。基于表面结构调控与反应过程耦合，建立表面改性抑制颗粒粘结的的技术原理和方法，为解决流态化气体还原炼铁的粘结失流问题提供理论基础及技术支持。