Thermal Characterization and Quantification of Calcium Carbonate Polymorphs

User Benefits

- The thermal behavior of the crystal polymorphs of calcium carbonate can be investigated by the DTG-60.
- The crystal polymorphs of calcium carbonate can be analyzed in a short time using ATR FTIR measurements.
- Even in the presence of multiple crystalline polymorphs, it is possible to separate and quantify closely located peaks using differential spectra in FTIR.

Introduction

CO₂-absorbing concrete is an innovative construction material which is expected to be used to achieve carbon neutrality. CO₂ can be sequestered by a process of carbonizing the calcium in concrete and absorbing CO₂ by forming calcium carbonate, and hardening concrete. This can contribute to suppressing global warming.
Calcium carbonate has three crystal polymorphs, calcite, aragonite, and vaterite. Because differences in the particle size and particle shape also affect the strength of concrete, it is important to understand and control the ratio of these polymorphs. From the viewpoint of CO₂ fixation, the thermal behavior of crystal polymorphs is also important information for understanding the amount of fixed CO₂ and the duration of fixation by thermal analysis.
In this article, a qualitative analysis and evaluation of the thermal characteristics of the polymorphs in calcium carbonate were carried out using a DTG-60 simultaneous TG/DTA, and quantitative analysis of the crystal polymorphs of calcium carbonate was conducted using a Fourier Transform Infrared Spectrophotometer IRTracer-100.

September 27, 2024 GMT