2025/04/11 by Arne Peys, Natalia Pires Martins, Fernando Prado Araujo +2 · 3 voices · 1 citation
Engineering · Materials Science · #Advanced ceramic materials synthesis #Concrete and Cement Materials Research #Magnesium Oxide Properties and Applications
paper · doi:10.1016/j.jcou.2025.103077
openalex publication_date 2025/04/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
The search for resources for low-carbon construction materials and valorization pathways for industrial residues go hand in hand. Mineral carbonation has been abundantly studied to strive for a net-zero CO 2 construction sector. Ferronickel slags have been studied for the production of other cementitious materials, but have inferior carbonation potential due to their low Ca-content. This work shows that the reactivity of a pyroxene-rich ferronickel slag towards CO 2 can be substantially increased using high-temperature slag engineering. Using a combination of CaCO 3 additions and slow cooling, the produced compacts made from synthesized slags acquire a compressive strength of 30–40 MPa after carbonation at 10 bar CO 2 and 60 °C for 16 hours. The reactivity towards CO 2 originates from the formation of akermanite (Ca 2 MgSi 2 O 7 ) during slag modification with > 20 wt% CaCO 3 . The compressive strength is dependent on the particle size distribution of the modified slag and carbonation time. Although the reaction degree of akermanite is high after 6 hours of carbonation, a significant strength increase is still seen after carbonation for 16 and 48 hours. The carbonation process forms a binding phase composed of aragonite and a CaMg-carbonate which might be high Mg-calcite or protodolomite. The CO 2 balance of the overall process shows a substantially lower value compared to Portland clinker-based cements, but additional efforts are required to develop an optimum net-zero CO 2 process. • Ferronickel slag was used as precursor for mineral carbonation. • High temperature modification increased the reactivity with CO 2 . • The akermanite phase causes the reactivity increase. • If sufficient akermanite, compressive strength > 30 MPa after carbonation. • Strength and CO 2 uptake optimized by finer milling and longer carbonation.