The Effects of Flocculation on the Propagation of Ultrasound in Dilute Kaolin Slurries

✍ Scribed by James C. Austin; Richard E. Challis

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 426 KB
• Volume: 206
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1998.5712

✦ Synopsis

A broadband ultrasonic spectrometer has been used to measure ultrasonic attenuation and phase velocity dispersion as functions of frequency in kaolin suspensions over a range of solid volume fractions from ‫؍‬ 0.01 to ‫؍‬ 0.08 and over a pH range from 3 to 9. The Harker and Temple theory was used to simulate ultrasound propagation in the suspension, using measured slope viscosity, particle size, and size distribution. Simulated results for ultrasonic attenuation and phase velocity agree well with measured values. Both sets of results agree well and show that for volume fractions above ϳ 0.05 attenuation and velocity dispersion increase for increasing floc size, whereas for volume fractions below ϳ 0.05 attenuation and velocity dispersion both decrease. It is proposed that the mechanism for this change in behavior around ϳ 0.05 involves changes in floc density and floc size distribution with and pH.