Sonication crystal cleavage

This procedure is applicable to other shapes. Crystal breakage by sonication may result in other types of crystal cleavage but three-dimensional growth may also be achieved in these cases. 

Figure 11-25 The unsonicated crystals are disrupted by sonication along cleavage planes.

Figure 11-25 shows the nature of that disruption. The unsonicated crystals (top) are disrupted by sonication along cleavage planes (bottom), a mechanism which produces few fines to elutriate out of the seed bed. For this product, the sonicators were located in the column bottom (Fig. 11-26). Whether the sonicators are located internally, as shown, or in a slurry flow system, as shown in Fig. 11-28, the crystal population fed to the sonicators is always drawn from the bottom of the seed bed, where the largest particles are located.

The astute observer wiU see that the fluidized bed crystaUization system shown in Fig. 11-21 has an unusual feature. Flow sonication units are in position to operate on pumped slurry from the seed beds. In other systems, the sonicators are located intemaUy in the bottom of the column. The sonifiers are power ultrasonic horns, which create sufficient cavitation and impact energy to break the crystals along cleavage planes. 

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