As global warming receives more and more attention, greenhouse gas carbon dioxide (CO2) emissions, capture and storage are also receiving increasing attention. Mineral carbonation technology refers to the acceleration reaction between alkaline minerals in nature with CO2 to form stable carbonates by specific technology. It has became a promising CO2 storage technology due to the stable and environmentally friendly carbonation products. However, natural minerals show low carbonation activity and low CO2 uptake. In addition, CO2 emitted from fossil fuel combustion requires a large amount of natural resources and high energy to form carbonates. The above-mentioned disadvantages hinder the development of mineral carbonation technology. Alkaline industrial waste such as steel slag is proposed to replace natural alkaline minerals for mineral carbonation. It provides a feasible way to reduce CO2 emissions, and also provides a new resolution for the utilization of industrial waste. The CO2 uptake and carbonation rate of steel slag are affected by many factors. In recent years, domestic and foreign scholars have done a lot of work to explore carbonation mechanism of steel slag, optimize the parameters of carbonation process, increase CO2 uptake, reduce energy consumption, and have achieved fruitful results. However, China produces a large amount of steel slag every year and the utilization is limited. If steel slag is only used for CO2 capture, it will increase the bulk density of steel slag and further increase the difficulty of steel slag treatment, and in addition, steel slag cannot be used efficiently. Therefore, many researchers have developed a carbonation curing technology to prepare building materials to realize the utilization of steel slag, in order to solve the problem of poor volume stability when steel slag is applied in building materials. Carbonation mechanism of steel slag, carbon sequestration ability and characteristics of different alkaline minerals in steel slag, and the mea-sures to increase carbon sequestration of steel slag are reviewed in this paper. In addition, the application of carbonated steel slag in building materials and the effects of carbonation on the mechanical properties and microstructure of steel slag are introduced. The prospects, technical difficulties and challenges of applying carbonated steel slag in building materials are discussed. © 2020, Materials Review Magazine. All right reserved.
