原料性能和配方对炭阳极生坯成型后膨胀行为的影响

The effects of raw material properties and formula on the expansion behaviors of carbon green anodes after forming

选取工业用三种煅后焦和两种沥青制备铝用预焙阳极生坯,采用实验室方法考察煅后焦和沥青性能、煅后焦粒度组成、沥青配比及混捏温度对阳极生坯成型后膨胀行为的影响。结果表明,沥青在糊料中比例越高,混捏温度越高,阳极生坯成型后体积膨胀越小;相对于中温沥青,改质沥青限制阳极生坯膨胀效果更好,且当改质沥青含量足够大时,阳极生坯会出现体积收缩;阳极生坯成型后膨胀与生坯密度并非直接关联,而与煅后焦闭气孔率成反比,与煅后焦真密度成正比。所获基础技术数据可供实际生产应用参考。

Three types of calcined cokes and two types of pitch were used to make carbon green anodes for studying effects of raw material properties and formula on the expansion behaviors of the green anodes after forming. Results show that the expansion of carbon green anodes can be reduced by increasing the ratio of pitch in paste and the kneading temperature. Comparing medium temperature pitches, the modified pitches have better capacity on reducing the expansion of green anodes. Green anodes will shrink when the content of modified pitches in the anodes is large enough. The expansions of green an- odes have affected by the synergy effects from the real density and the closed porosity of calcined cokes. The expansions of green anodes are not directly associated with the density of green anodes. They can decrease with increasing the closed porosity of cokes or decreasing the real density of calcined cokes. The obtained data can be useful in improving the anode quality and reducing its cracking.