复合型抗氧化剂对预焙阳极材料抗氧化性能的影响

Influence of Composite Antioxidants on Oxidation Resistance of Prebaked Anode

首次提出了在预焙阳极材料用煤沥青输送至熔化槽脱水前直接添加抗氧化剂的方法并制备了新型预焙阳极材料。通过扫描电子显微镜(SEM)检测和抗氧化性能分析等方法表征了预焙阳极材料的显微结构、氧化度以及添加抗氧化剂前后沥青的微观结构,并探讨了预焙阳极材料的抗氧化机理。结果表明:添加1%的AlF3/Li2CO3(AlF3与Li2CO3质量比为2∶3)的预焙阳极材料的体积密度达到1.55 g/cm3,经过900℃煅烧后其氧化度值仅为15.7%,比不添加抗氧化剂的预焙阳极材料的氧化度值降低了10.6%。在沥青炭化成焦过程中,这种复合型抗氧化剂镶嵌在炭质本体中,使得沥青焦与石油焦的活性状态趋于一致,直接降低了沥青焦中不饱和键的活性点数量,阻挡O2、CO2等氧化性气氛与阳极接触面微孔的接触,从而减少预焙阳极材料的过量消耗。

It was presented for the first time that antioxidant was directly added to pitch binder for anode prebake when the binder was transported to melting tank.New type prebaked anode material was prepared by this way.The oxidation degree and microstructure of prebaked anode and the microstructure of pitch before and after the addition of antioxidant were investigated by scanning electron microscope（SEM） and oxidation resistance analysis.The antioxidant mechanism of prebaked anode was discussed as well.The results showed that,compared with perbaked anode without antioxidant,volume density of that with addition of 1% AlF3/Li2CO3（at a mass ratio of 2∶3） reached 1.55 g/cm3 and its oxidation degree was only 15.7% after calcination at 900 ℃,decreasing by 10.6%.During the carbonization of pitch into coke,the composite additive was inserted into carbon,making the activity of pitch coke consist with that of petroleum coke.It directly cuts down active sites of unsaturated bond in pitch coke and prevents micro-pores on the contact surface of prebaked anode from oxidizing atmospheres such as oxygen and carbon dioxide to reduce excess consumption of prebaked anode.