除尘灰润磨预处理对其所制球团质量的影响

除尘灰因经过高温处理,具有孔隙发达、表面粗糙、疏水性强等特点,使得采用常规方法造球时,球团性能指标低。为提高球团性能,采用润磨工艺对除尘灰进行预处理。结果表明,当润磨时间为9 min时,与未进行润磨处理比较,生球落下强度和抗压强度分别从9.2次、20.09 N/个提高到30.5次、30.78 N/个,干球落下强度和抗压强度分别从0.7次、52.44 N/个提高至2.1次、86.42N/个,群落粉化率从18.42%降低至5.23%。润磨后的除尘灰微细颗粒含量增加,比表面积增大,造球时母球发生兼并聚集的可能性降低,母球更趋向于吸收微细粒粉料而逐渐长大,所制球团质量高。

Effects of Damp Milling Pretreatment Fly Ash on Properties of the Pellets

Due to the high temperature treatment，fly ash has the characteristics of multipore，rough surface，high hydrophobic etc.and because of which the pellets has poor properties by conventional methods of pelletization.In order to improve the properties of pellets，damp milling methods is applied for the pretreatment of fly ash.The results indicated that，compared with non damp milling operations，while damp milling for 9 min，drop strength and comprehensive strength of green pellets increased from 9.2 times，20.09 N/P to 30.5 times，30.78 N/P，drop strength and comprehensive strength of dry pellets increased from 0.7 times，52.44 N/P to 2.1 times，86.42 N/P，pulverization rate decreased from 18.42% to 5.23%.After damp milling，there are more microfine particles and larger specific surface in fly ash，which decrease the mergers and acquisitions possibility of mother balls.The mother balls tend to absorb the microgranular powder and gradually grown up，making the pellets possess high quality.