超声辐照前后煤浆粒度分布变化研究

STUDY ON THE CHANGE OF PARTICLE SIZE DISTRIBUTION BEFORE AND AFTER IRRADIATION

选用红会、大同及兖州煤制备水煤浆 ,考察了超声辐照前后煤浆粒度分布变化 ,并研究了超声辐照前后粒度分布变化对煤浆表观粘度、流变特性及静态稳定性影响 .在超声辐照强度为 80 W/ cm2 ,频率为 2 0 k Hz的条件下 ,超声辐照导致煤浆中 1 0 0 μm以下的细级煤粒的比例明显增加 .实验结果表明 ,超声辐照对煤浆具有很强的分散作用 ,在一定的粒度范围 ,细级煤粒的增加有利于煤浆流变性能的改善 。

The change of particle size distribution(PSD) in coal water slurry (CWS) before and after irradiation was investigated in the present paper.The experiments indicated that ultrasonic irradiation resulted in a higher proportion of fine coal in CWS as compared with that in absence of ultrasonic irradiation.The specific surface area of coal particles was therefore increased as the increase in the fine coal by ultrasonic irradiation.The use of 1% additive did not meet the saturated Langmuir adsorption of additive on the surface of coal particles,resulting in an increase in the apparent viscosity of CWS.Improvement on rheological behavior of CWS by irradiation was related to the change of PSD before and after irradiation.According to Stokes equation,the particle size played a key role to the static stability of CWS.As effect of the gravity on the coal particles in CWS decreased with the increase in the proportion of fine coal,the static stability of CWS was distinctly improved.