燃煤飞灰物理化学特性及其润湿机理研究

以小龙潭电厂燃煤飞灰及其不同粒径范围的分级灰为对象,采用X射线荧光光谱、X射线衍射、离子色谱、Zeta电位、扫描电镜等实验方法研究了飞灰的物理化学特征.同时采用沉降实验、表面张力实验研究了三种不同润湿剂对飞灰的润湿性能.研究发现,溶液对飞灰的润湿能力不仅取决于其气液界面张力,还与飞灰的组成、表面电位以及形貌特征密切相关.亲水性物质含量的增加,颗粒表面电荷与润湿剂分子间的静电吸引,颗粒表面的棱角孔隙等均可以促进其润湿;温度越高飞灰润湿性能越好,且温度对飞灰润湿过程影响较大,温度较高(60℃)时润湿剂种类及浓度对飞灰润湿过程的影响不明显.

STUDY ON PHYSICOCHEMICAL CHARACTERISTIC AND WETTING MECHANISM OF FLY ASH IN COAL FIRED POWER PLANT

The physicochemical characteristics of fly ash and their diameter separation fraction from Xiaolongtan power plant has been studied with X-ray fluorescence spectrometry,X-ray diffraction,ion chromatography,zeta potential and scanning electronic microscopy.Sedimentation experiments and surface-tension tests have been adopted to study the wettability of fly ash in three difierent wetting agents.The results indicate that wettability of fly ash in solution depends not only on the gas-liquid surface tension,but also on composition,surface potential,and particle morphology of fly ash.Increasing of hydrophilic mineral content,electrostatic attraction between particles and wetting agent molecules,edges of particles,and pores on the ash surface can make wetting more easily.Better wettability of fly ash particles exhibit with increasing temperature of the wetting agents.Wettability of fly ash is greatly affected by temperature,it can hardly be changed by agents type and concentration at a higher temperature of such as 60℃.