Production of low-carbon amorphous SiO2 for use as a supplementary cementitious material and nesquehonite from olivine

• Published in: Materials letters Vol. 361; p. 136133
• Main Authors: Shanks, Barney, Howe, Caitlin, Draper, Sam, Wong, Hong, Cheeseman, Christopher
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-04-2024
• Subjects: Amorphous silica; Carbon sequestration; Low-carbon cements; Nesquehonite; Olivine; Olivine; Low-carbon cements; Nesquehonite; Amorphous silica; Carbon sequestration
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2024.136133

•Silica and nesquehonite are produced by acid dissolution of olivine.•The silica formed is a viable supplementary cementitious material.•Nesquehonite formation by carbonation makes the process carbon negative.•Global reserve of olivine means this is a viable route to low-carbon concrete.
Amorphous silica and hydrated magnesium carbonate (nesquehonite, MgCO3·3H2O) have been produced by acid dissolution of olivine ((Mg,Fe)2·SiO4). The amorphous silica is a viable supplementary cementitious material, and the formation of nesquehonite by carbonation, results in a carbon negative process. Using the amorphous silica as a supplementary cementitious material produces low-carbon cement. The global reserve of olivine makes this a viable route to producing low-carbon concrete.