改质沥青——煤焦油粘结剂添加B_4C对铝用炭间糊性能的影响

以改质沥青—煤焦油混合粘结剂为基体,添加B_4C制备改性粘结剂,并以电煅无烟煤、沥青焦、熟碎为骨料和改性粘结剂制备铝电解用炭间糊,研究B_4C添加量对制备炭间糊性能及微观结构的影响。结果表明,随着B_4C添加量的增加,制备炭间糊的灰分、电阻率、耐压强度、残炭率逐渐增大,挥发分、膨胀/收缩率、失重速率逐渐减小;B_4C在高温下与O_2、CO等小分子化合物发生化学反应,生成的氧化硼高温熔融,可以有效减缓粘结剂热解缩聚产生的体积变化和快速失重,并改善粘结焦的致密程度;当B_4C添加量为3%时,制备炭间糊具有较佳的综合性能。

Effect of Modified Pitch-Coal Tar Mixed Binder with B4C on Properties of Ramming Paste for Aluminum Electrolysis

Modified binder consists of modified pitch and coal tar mixed with boron carbide powders. Ramming paste was synthesized applying modified binder and calcined anthracite coal, coal derived pitch coke, baked scrap as aggregates. Effect of B4C addition on properties and microstructure of ramming paste were investigated. The results indicate that increasing addition of B4C, results in rises of ash, electrical resistivity, compressive strength and carbon yield, and drops of volatile matter and expansion/shrinkage. Obtained through high temperature chemical reaction between B4C and small molecular compounds such as O2, CO, B2O3 can reduce volume change and weight loss rate of ramming paste, and improve compact degree of binder coke. The optimal comprehensive properties of ramming paste are obtained with addition of B4C of 3%.