CO2 mineralization by calcium silicate and Portland cement materials

Anhydrous calcium silicate encompasses a series of mineral phases, namely tricalcium silicate (C 3 S), dicalcium silicate (β-C 2 S and γ-C 2 S), tricalcium disilicate (C 3 S 2 ), and monocalcium silicate (CS). C 3 S and β-C 2 S, characterized by high hydraulic reactivity, constitute the primary components of Portland cement, finding ubiquitous application in the construction and building materials industries. With the growing demand for low-carbon building materials, research on low-lime calcium silicate minerals, including γ-C 2 S, C 3 S 2 , and CS, has captured increasing attention. Whether hydraulic or non-hydraulic, these calcium silicate minerals exhibit remarkable carbonation reactivity, creating a new path for the development of low-carbon cementitious materials through CO 2 activation. The carbon mineralization of calcium silicate minerals is an intricate process, being subject to the influence of a plethora of factors. These factors include, but are not limited to, temperature, moisture content, CO 2 concentration, CO 2 pressure, and additives. Additionally, the properties of the carbonation products play a decisive role in the final hardening performance of the carbonated materials. This chapter explores the carbonation reactivity and the fundamental carbonation mechanism of calcium silicate minerals, analyzes various factors influencing the carbonation degree, and reveals the properties and control strategies of carbonation products.