TRACING THE CENTRIFUGAL SEPARATION OF FINE-PARTICLE SLURRIES - LUM at AFS 2005

AFS-meeting

Effect of centrifugal acceleration, particle interaction and concentration

T. Sobisch*, D. Lerche, T. Detloff, L.U.M. GmbH, Berlin,

www.lum-gmbh.com, info@lum-gmbh.de

M. Beiser, A. Erk, Institut für Mechanische Verfahrenstechnik und Mechanik,

Universität Karlsruhe (TH)

Conclusion

Multisample analytical batch centrifugation with optical detection proved to be a versatile tool for the characterization of the separation of fine grained materials. This holds for information on the type of sedimentation behaviour (free sedimentation of individual particles, hindered settling, zone settling), on the sedimentation velocity distribution inside the centrate and on the packing, compression and elasticity behaviour, on the nature of particle interactions and the degree of flocculation as well.

The investigations were complemented by centrifugation with manometric detection and with a disk centrifuge. The first allows a high resolution in the determination of velocity distributions up to high values of velocities in the order of several mm/seconds and high particle concentrations, the second represents a cross section of a solid bowl centrifuge and allows to study the movement of the phase boundary after abruptly discharging a sample into the spinning centrifuge.

The results of multisample analytical centrifugation with optical detection were in good agreement with the complementary methods (velocity distribution determined by manometric detection and average packing density obtained during compression in the disk centrifuge).