| Project Detail |
Nearly 580 million tonnes per year (Mt/y) of ferrous metallurgical slags (FMS) are produced as by-products of iron, steel, and alloy production. The accelerated reaction of CO2 with Ca/Mg present in these FMS can result in the formation of Ca/Mg-carbonates, offering a relatively simple and low-energy pathway for CO2-abatement. This CO2-mineralization process has the capacity to directly sequestrate ~140 Mt-CO2/y globally, leading to the potential availability of ~720 Mt/y of carbonated-FMS as a by-product. The carbonated-FMS are expected to be rich in amorphous alumina-silica and Ca/Mg-carbonates: when used in combination with Ordinary Portland Cement (OPC), they are expected to form a composite cement similar to the presently marketed Limestone-pozzolana-OPC cement. In this context, this study focuses on the utilization of the carbonated-FMS to produce low-carbon cement with potential CO2-avoidance of ~500 Mt-CO2/y.
To maximize the cementitious reactivity, the carbonation mechanism will be studied using different types of FMS and synthetic analogues of the major Ca/Mg-rich minerals present in them. The CO2-mineralization process and environment will be optimized to maximize the cementitious reactivity of carbonated-FMS by controlling their phase compositions, microstructures, and morphologies. When introduced as supplementary cementitious material (SCM), its hydration reaction with OPC will be studied to maximize its
utilization potential. For the final mortar/concrete products containing carbonated-FMS, the environmental leaching will be studied. Moreover, pathways for the end-of-life recycling of the product will be analyzed through cradle-to-cradle scenario analyses. Finally, for easy acceptance by the practitioners, the product will be subjected to detailed life-cycle analyses and environmental impact assessments. |
