The effect of ultrasonic field on calcium carbonate scale formation

A retardation effect (62-76%) was observed on the crystallization of calcium carbonate in the presence of an ultrasonic applied field (0.56 w/cm(2)). The apparent order of crystal growth of calcite was found to be n= 2 +/- 0.2 for the seeded growth experiments and n= 6.7 +/- 0.2, n= 5.3 +/- 0.1 for the spontaneously precipitated vaterite in the absence and presence of the ultrasonic field, respectively. The mechanism, the nature, the morphology and the size of the crystals formed was not influenced by the applied ultrasonic field, which may possibly affect the dehydration step of the growth units or the migration step of the dehydrated growth units to the active growth sites. (C) 2001 Elsevier Science B.V. All rights reserved.