Preparation of Spherical CaCO₃ (Vaterite) Powder and Transition to Calcite in Water

Abstract

The precipitation conditions for obtaining spherical particles of one-phase vaterite have been determined, and the effects of additives during precipitation and transition on the transition isotherms have been studied with the spherical powders obtained with different precipitants such as Na₂CO₃ and (NH₄₎₂CO₃.
The transition from vaterite to calcite in water media is characterized by abrupt appearance of calcite particles having well-developed crystal habits. Summarizing the experimental data, it is proposed that the dissolution-precipitation mechanism is operative in the transition, in which dissolution process is probably a rate-determining step.