Synthesis of Giorgiosite [Mg5(CO3)4(OH)2·5–6H2O], further light on a new hydrated magnesium carbonate for MgO-based cement
Nguyen, H.; Bernard, E.; Winnefeld, F.; Lothenbach, B.; Kinnunen, P.
Nguyen, H.
Bernard, E.
Winnefeld, F.
Lothenbach, B.
Kinnunen, P.
Thailand Concrete Association
Nguyen, H.; Bernard, E.; Winnefeld, F.; Lothenbach, B.; Kinnunen, P. Synthesis of Giorgiosite [Mg5(CO3)4(OH)2·5–6H2O], further light on a new hydrated magnesium carbonate for MgO-based cement. In: Thailand Concrete Association, Ed. Further Reduction of CO2 -Emissions and Circularity in the Cement and Concrete Industry, 16th International Congress on the Chemistry of Cement 2023 - ICCC2023 (Bangkok 18.-22.09.2023). Bangkok, 2023. Available at: https://www.iccc-online.org/archive/
https://creativecommons.org/licenses/by-nd/4.0/
All papers in the 2023 conference proceedings are published under the license CC-BY-ND 4.0. (https://creativecommons.org/licenses/by-nd/4.0/legalcode)
https://creativecommons.org/licenses/by-nd/4.0/
All papers in the 2023 conference proceedings are published under the license CC-BY-ND 4.0. (https://creativecommons.org/licenses/by-nd/4.0/legalcode)
https://creativecommons.org/licenses/by-nd/4.0/
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:oulu-202410096229
https://urn.fi/URN:NBN:fi:oulu-202410096229
Tiivistelmä
Abstract
Giorgiosite is a relatively unknown hydrated magnesium carbonate (HMC) without a clear understanding of its characteristics and synthesis pathway. The phase has a nano-wire morphology with high surface area, and hence, attracts immediate interests for various applications including as early-strength-giving phase in HMC-based binder. However, there had been no clear and successful pathway in the past to synthesize the phase. The present work addresses this research gap and reports an effective protocol to obtain giorgiosite in high purity. We found that giorgiosite can be synthesized via the conversion of pure nesquehonite [MgCO3·3H2O] in a 1M Mg-acetate solution at 50 °C. In contrast, nesquehonite converted to dypingite [Mg5(CO3)4(OH)2·5H2O] in the absence of acetate. Here, the characteristics of giorgiosite as determined by XRD, TGA/FTIR, SEM, and Raman spectroscopy are reported. The better understanding of the characteristics of giorgiosite will contribute to the development of HMC-based binders, which have the potential to be a carbon-negative construction material. Further work is needed to shed light on the conversion pathway in the presence of organic ligand (e.g., acetate) and to determine the thermodynamic properties of giorgiosite.
Giorgiosite is a relatively unknown hydrated magnesium carbonate (HMC) without a clear understanding of its characteristics and synthesis pathway. The phase has a nano-wire morphology with high surface area, and hence, attracts immediate interests for various applications including as early-strength-giving phase in HMC-based binder. However, there had been no clear and successful pathway in the past to synthesize the phase. The present work addresses this research gap and reports an effective protocol to obtain giorgiosite in high purity. We found that giorgiosite can be synthesized via the conversion of pure nesquehonite [MgCO3·3H2O] in a 1M Mg-acetate solution at 50 °C. In contrast, nesquehonite converted to dypingite [Mg5(CO3)4(OH)2·5H2O] in the absence of acetate. Here, the characteristics of giorgiosite as determined by XRD, TGA/FTIR, SEM, and Raman spectroscopy are reported. The better understanding of the characteristics of giorgiosite will contribute to the development of HMC-based binders, which have the potential to be a carbon-negative construction material. Further work is needed to shed light on the conversion pathway in the presence of organic ligand (e.g., acetate) and to determine the thermodynamic properties of giorgiosite.
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