Amorphous and crystalline CaCO3 phase transformation at high solid/liquid ratio – Insight to a novel binder system

Isabel Galan*, Bettina Purgstaller, Cyrill Grengg, Bernhard Müller, Martin Dietzel

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The transformation reactions in aqueous calcium carbonate systems are relevant for biomineralization processes, functionalised materials design and recently for the potential development of inorganic binders. The so-called ‘calcium carbonate cements’ are obtained by mixing amorphous (ACC) and crystalline CaCO3 (herein the anhydrous minerals calcite, aragonite and vaterite) with low amounts of water. The mechanisms behind the setting and hardening of these binders are still not clear. In the present study, the dissolution and precipitation reactions in low water ACC systems with and without crystalline CaCO3 have been investigated by in-situ techniques, Raman spectroscopy and optical pH measurements, coupled with reaction time resolved mineralogical and chemical analyses of solid and liquid samples. The results clearly indicate the presence of initial crystalline CaCO3 polymorphs to control the reactions kinetics and the resulting individual microstructure. Vaterite, with a considerably higher surface area than calcite and aragonite, produces more bonded and connected material. In the ACC-vaterite system the transformation of vaterite to calcite takes places in two dissolution-precipitation stages, accompanied by typical pH in- and decreases. Time-resolved analyses and hydrochemical modelling clearly reveal the solid transformation behaviour to be governed by the presence/absence of Mg2+ in the solution and the impurities, such as Na+, liberated from the educts to the reactive solution. The control and adjustment of the identified influencing parameters could allow for promising future development of CaCO3-based binders.

Original languageEnglish
Article number126465
JournalJournal of Crystal Growth
Publication statusPublished - 15 Feb 2022


  • A1. Crystal morphology
  • A1. In situ Raman spectroscopy
  • A1. Optical pH sensor
  • A2. Growth from solutions
  • B1. Amorphous calcium carbonate
  • B1. Calcium carbonate cement

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Inorganic Chemistry
  • Materials Chemistry


Dive into the research topics of 'Amorphous and crystalline CaCO3 phase transformation at high solid/liquid ratio – Insight to a novel binder system'. Together they form a unique fingerprint.

Cite this