基于图像分析的铝用炭阳极孔隙结构特征与阳极碳消秏机理研究

This proposal is aimed at the need for low-carbon development of aluminum smelters with focusing on the problem of carbon consumption of prebaked anodes in aluminum reduction cells for today. Two scientific problems have been established on 1) image analysis based characterization of porous structures of the prebaked anodes and the kinetics of air/CO2 reaction processes, and 2) the mixing method with interfacial behaviors between the coke particle and pitch liquid and the mechanism of enhancing the oxidation resistance of and the combination strength of the coke particle and pitch liquid for the anodes. The investigation is to establish a relationship between the porous structure and the reactions of air and CO2, develop a model that can make balance among various components in chemical activity and inhabiting the selective reactions as well. In addition, a simulation model will be developed for checking the green anode quality and abnormality. In such a way, a new manufacturing technology for the prebaked anodes with low carbonconsumption will be generated from this work and thus contribute to the sustainable development of low carbon metals production.

本项目紧密围绕铝工业低碳发展的需求，针对铝电解槽预焙阳极碳消耗问题，凝练出（1）基于图像分析的炭阳极孔隙特征与阳极组分空气/CO2反应性均衡调控机制（2）沥青/焦粒间表界面包覆层配合模式与骨料颗粒-黏结剂结合强化机制两个科学问题进行研究，探索阐明基于图像分析的炭阳极孔隙特征参数与减少空气/CO2反应性和强化炭阳极骨料-黏结剂结合的关系，构建可均衡各组分氧化活性、抑制选择性氧化作用及减少阳极碳粒的低碳消耗量调控模式，以及基于计算机模拟的阳极成型应力和开裂分析诊断，系统性创新预焙阳极材料组成设计和制备工艺优化，为发展一种低碳耗铝用预焙阳极制备和应用的新技术途径提供科学基础。

本项目紧密围绕铝工业低碳发展的需求，针对铝电解槽预焙阳极碳消耗中有关阳极孔隙特征与反应性、沥青黏结剂/骨料焦粒间表界面配合强化机制的科学问题进行研究，基于图像分析方法分析精细表征了孔隙率、孔隙直径、形状因子、孔隙分形和配位数等多种孔隙结构参数，发现对石油焦煅烧调质处理、利用颗粒形态参数优化装填性能、合理调控骨料煅烧与阳极焙烧的温度差别及孔隙参数，可均衡降低阳极各组分氧化活性、减少碳粒掉渣；阐明了阳极内部孔隙结构参数变化、CO2氧化的化学反应活化能和气体扩散活化能的耦合作用导致沥青焦优先氧化的机理；反应动力学表明随着二氧化碳反应持续进行，表观活化能由230kJ/mol减小到201kJ/mol，其中沥青焦相表观活化能小于石油焦相，证实阳极反应掉渣是由于多孔状沥青焦被优先氧化与孔隙结构特征及阳极碳消耗率之间的本质联系；结合阳极从配料、混捏、焙烧全寿命孔隙结构演变及碳消耗的系统关联、氧化石墨烯的改性作用、对工业炭阳极成型裂纹的的模拟诊断都为探索改进阳极组成设计与氧化过程动力学均衡调控机制，减少阳极的碳消耗提供了新的科学基础和应用潜力。