熔渣体系中铬铁合金界面保护层形成机制及阳极析氧机理研究

The development and application of inert anode in the process of molten oxide electrolysis will completely solve the problem of CO2 emission during the iron and steel smelting process based on carbon reduction. Due to improve the electrochemical efficiency and product purity, reduce carbon emissions and other advantages, the Cr-Fe alloy was applied in high-temperature molten oxide electrolysis successfully, which provides a new way for the selection and optimization of high temperature inert alloy anode materials. In this project, focuses on the interfacial reaction and the electrode process between the Cr-Fe alloy and molten CaO-Al2O3-MgO slag. The formation mechanism of the protective oxide layer on the surface of the Cr-Fe alloy and the electrochemical oxygen evolution mechanism of the anodic process were investigated. The interface reaction behavior and regulation mechanism between the metal alloy and molten slag under the electrochemical conditions will be making known. More importantly, the new understanding of the anode inert process and oxygen evolution reaction of metal alloy in molten slag were obtained. There all can improve the service life and electrochemical efficiency of the Cr-Fe alloy during molten oxide electrolysis process. It also provides scientific basis for the research, development and application of ultra-high temperature inert alloy anode in slag electrochemical system.

熔融氧化物电解过程中惰性阳极的开发和运用，将彻底解决基于碳还原的钢铁冶炼过程中CO2的排放问题。高温、高导电、高耐蚀性及相对廉价的铬铁合金在高温熔融氧化物电解过程中的成功运用，则为高温惰性合金阳极材料的选择和优化提供了新途径。本项目围绕铬铁合金惰性阳极与CaO-Al2O3-MgO基熔渣的界面反应及电极过程开展相关研究，重点研究铬铁合金表面保护性氧化层的形成机制和阳极过程电化学析氧机理，揭示金属合金表面氧化层形成过程和演化规律，阐明电化学条件下熔渣与金属合金界面反应行为及其调控机制，获得金属合金惰性阳极界面析氧反应的新认识，提高铬铁合金在熔融氧化物电解过程中的使用寿命和电化学效率。也为熔渣电化学体系中超高温惰性合金阳极研究、开发和应用提供科学依据。

基于电子传递作为能量载体的熔融氧化物电解技术，有望解决基于碳还原的钢铁冶炼过程中CO2的排放问题。高温、高导电、高耐蚀性及相对廉价的铬铁合金在高温熔融氧化物电解过程中的成功运用，则为高温惰性合金阳极材料的选择和优化提供了新途径。本项目围绕铬铁合金惰性阳极与 CaO-Al2O3-MgO基熔渣的界面反应及电极过程开展相关研究，通过探讨熔渣体系中铬铁合金界面反应层的形成和演化规律，表明其表面生成的物质主要以Fe、Cr以及添加的熔渣中的金属的氧化物为主，生成FeCr2O4尖晶石相对合金进行保护，揭示了界面反应层对提高金属合金耐蚀性能机理；外加电流条件下的熔渣/铬铁合金间的界面润湿为反应型润湿，外加电场能够降低熔渣/铬铁合金间接触角从而改善熔渣/铬铁合金间的润湿特性，揭示了电极过程对合金界面反应层的调控机制；熔渣电化学体系中铬铁合金阳极界面反应过程中不同电位对氧离子的迁移过程作用不同，正电位起促进作用，负电位起阻碍作用；该电化学体系容抗随着过电势的增加而逐渐减小，有利于析氧过程的进行，获得高温条件下析氧过程的电极界面反应动力学参数，形成了金属合金惰性阳极界面析氧反应的新认识，有利于提高铬铁合金在熔融氧化物电解过程中的使用寿命和电化学效率。本课题研究结果将有利于金属合金惰性阳极在低碳电化学冶金技术中的应用，为熔渣电化学体系中超高温惰性合金阳极研究、开发和应用提供科学依据。