Abstract: The carbon anode is prepared by baking a mixture of petroleum coke aggregate and pitch at 180℃ for use in the aluminum industry. Due to its good wettability and environmental friendliness towards carbon anode aggregates, the biopitch is considered as a promising carbon anode binder. The biomass conversion technology, substituting traditional coal tar pitch with biopitch, partially or completely in the aluminum production, has recently received domestic and foreign researchers' attention. However, the biopitch typically has a lower coking value which may have a negative impact on its performance. In this work, alumina additives have been added to the biopitch anode to improve its performance. In order to understand the effect of alumina additives on the performance of biopitch anodes, biopitch anode materials were prepared by hot pressing and sintering in the laboratory with alumina as a catalyst. The CO2 reactivity of the anodes was tested with a thermogravimetric analyzer in laboratory. The influence of additives on the performance of the anodes and the CO2 reactivity as well as the wettability of biopitch on petroleum coke were studied by X-ray diffraction analysis, optical microscopy (OM) and high-resolution transmission electron microscopy (HRTEM). The results indicated that the biopitch exhibited better wettability than coal tar pitch with the same surface tension and viscosity. In addition, a transformation occurred from initially less well-ordered to ordered structure for the biopitch anode with alumina additives during baking, thereby increasing the coking value of the biopitch, reducing the CO2 reactivity of biopitch anodes and improving their antioxidant properties. Accompanied by an enhancement in the graphitization degree and an increase of carbon structural orders, the performance of biopitch anodes has been improved significantly with alumina as additives. The biopitch could be used to replace 100% of the coal tar pitch in a carbon anode recipe. This study has provided a theoretical guidance for the application of biopitch anodes and the reduction of energy consumption in aluminum electrolysis.

Key words: aluminum electrolysis, biopitch, carbon anode, wettability, coking value

摘要： 为了深入探究氧化铝添加剂对生物沥青阳极性能的影响，本工作通过热压烧结制备了添加氧化铝的生物沥青阳极材料，并对制备的阳极进行气化反应实验，结合光学显微镜、XRD、HRTEM等微观分析手段，研究了生物沥青对石油焦的润湿性、添加剂对生物沥青阳极气化反应性以及添加剂对生物沥青阳极性能的影响。结果表明，在相同表面张力和黏度下，生物质沥青比煤沥青表现出更好的润湿性。氧化铝能够提高生物沥青的产焦率，从而降低生物沥青阳极的气化反应性，提高抗氧化性。氧化铝还可以提高生物沥青阳极的石墨化程度，改善阳极试样的原子排列有序度，从而提高阳极材料的性能。本研究为生物沥青阳极的工业应用以及降低工业生产能耗提供了理论指导。

关键词: 铝电解, 生物沥青, 碳阳极, 润湿性, 焦化值