Morphological development in calcium carbonate precipitation by the ethanolamine process

Morphological development in calcium carbonate precipitation by the ethanol amine process at 30 and 60 degrees C has been examined using different tech niques (quantitative image analysis, laser diffraction, XRD, and FT-IR). Th e initially grown phase is of vaterite modification that at higher temperat ures (60 degrees C) transforms to a more stable aragonite phase within the reactor itself. A comparison of the form and structure of calcium carbonate particles obtained during the process leads to a conclusion that crystal a ggregation is the mechanism that determines the overall particle size at lo wer temperatures (30 degrees C), while crystal growth dominates at higher t emperatures. The results show that crystal characterization by quantitative image analysis permits a better understanding of the phenomena taking plac e in the reactor. (C) 1999 Elsevier Science S.A. All rights reserved.