Energy Generation from Waste Slags: Beyond Heat Recovery

Abstract

In this study, metallurgical and gasification slags mixed at a specific composition were heated to a slag discharge temperature range (i.e., tap out temperatures in iron & steelmaking) in the presence of CO₂, resulting in a reaction generating energy — enough to convert CO₂ to CO which can be used in other processes such as ore reduction, gas turbine power generation, and synthetic liquid/gaseous fuel production. Computational simulations suggested that the generation of H₂ from H₂O would also be possible using the same mixed slag approach at no additional heat supply. Energy generated from the reaction remains largely in excess after conversion (CO₂ to CO), which can be utilized independently for or support other processes. Furthermore, a final slag volume is expected to decrease to about 30%, dramatically decreasing landfill burden.