粉磨方式对粉煤灰理化特性的影响

Influence of grinding method on physicochemical properties of fly ash

为提升粉煤灰综合利用效率,采用球磨机和蒸汽动能磨对粉煤灰进行粉磨,对比2种粉磨方式所得粉煤灰的粒度、比表面积、活性指数、球形颗粒余量、物相组成和化学组成等特性,以及2种粉磨方式的能耗与粉磨效率。结果表明:与球磨机相比,通过蒸汽动能磨所得的粉煤灰微粉的粒度更小,中位径达2.25μm,比表面积可达1 110.5 m^(2)/kg,粉煤灰的活性指数更高,最高可达107.7%;蒸汽动能磨和球磨机不会改变粉煤灰的物相组成,但会降低粉煤灰中矿物结晶度;随粉磨强度的增加,粉煤灰粒度减小,晶体结晶度降低;粉磨破坏粉煤灰微珠颗粒,释放出内部Ca、 Si、 Al等成分,提升Si、 Al释放率,优化粉煤灰微粉的化学组成,强化水化反应;蒸汽动能磨的粉磨效率更高、耗能更少。

In order to improve the comprehensive utilization efficiency of fly ash,a ball mill and a steam kinetic energy mill were used to grind fly ash.The particle size,specific surface area,activity index,remaining amount of spherical particles,phase composition and chemical composition of fly ash obtained by the two grinding methods were compared,as well as energy consumption and grinding efficiency of two grinding methods.The results show that compared with the ball mill,the particle size of fly ash powder obtained by steam kinetic energy grinding is smaller,the median diameter can reach 2.25μm and the specific surface area can reach 1110.5 m^(2)/kg.The activity index of fly ash is higher and up to 107.7%.The phase composition of fly ash will not be changed and the crystallinity of minerals in fly ash will be reduced by steam kinetic energy mills and ball mills.As the grinding intensity increasing,the particle size is reduced and the crystallinity is reduced too.The grinding destroys the particles of fly ash and releases internal components such as Ca,Si and Al,which improves the release rate of Si and Al.The chemical composition of fly ash powder can be optimized and the hydration reaction can be strengthened.The steam kinetic energy mill has a higher grinding efficiency and a smaller energy consumption.