Abstract: Three different types of Malvern laser particle size analyzer were used to investigate the effects of particle refractive index, shading index, stirring rate of disperser, ultrasonic wave and window cleanliness on the particle size distribution of S Zorb adsorbent. The optimum conditions for particle size analysis of S Zorb adsorbent covered a particle refractive index of 2.18―1.0i, a shading index of 10%—15%, and a stirring rate of 3 000 r/min using MS3000 laser particle analyzer with HydroEV wet disperser,a stirring rate of 2 500 r/min using MS2000 laser particle analyzerwith HydroMU wet disperser,or a stirring rate of 900 r/min using MS2000 laser particle analyzer with 2000G wet disperserand conveying pump speed of 2 200 r/min, respectively. Ultrasonic dispersion will seriously damage the original appearance of adsorbent particles, so ultrasonic should not be used in the test. The cleanliness of the window of the laser particle analyzer has a great influence on the particle size analysis results of the adsorbent. The suitable pretreatment condition of the spent adsorbent is drying at 200 ℃ for 8 h. Too high pretreatment temperature will cause sintering of particles, leading to wrong results of particle size distribution.

Key words: S Zorb, laser light scattering, sorbent, particle size distribution