Experimental of CO2 mineralization by industrial containing calcium solid wastes
Under the background of emission peak and carbon neutrality,CO2 mineralization has attracted more attention as an effective carbon sequestration technology.For six kinds of industrial calcium-containing solid wastes,ammonium chloride solution was used to leach and prepare mineralization mother liquor,and then the direct and indirect mineralization experiments of CO2 in simulated coal-fired flue gas were carried out at room temperature and pressure.The mineralization efficiency and mineralization products of six kinds of solid wastes were analyzed in detail,and the circulation ability of leaching agent to leach calcium-containing solid wastes was tested.The results showed that the leaching rate of Ca2+in the six solid wastes was between 18.88%and 95.15%due to the different types and contents of calcium-containing mineral phases.The concentration of Ca2+in the leaching solution was purified ash>sintering red mud>coal fired fly ash 2>coal fired fly ash 1>drying ash>Bayer red mud.After cyclic leaching of purified ash,coal fired fly ash 2 and sintering red mud by ammonium chloride solution,the indirect mineralization efficiency of coal fired fly ash 2 and purified ash only decreased by 1.44%and 1.34%with the increase of the number of cycles,while the indirect mineralization efficiency of sintering red mud decreased by 6.21%.Among the six kinds of solid waste,the calcium carbide purification ash had the highest indirect mineralization efficiency of 57.60%,and the sintering red mud had the highest direct wet mineralization efficiency of nearly 67.25%.The product of CO2 indirect mineralization was rhombohedral calcite with a particle size of 2-5μm.
leachingmineralizationcarbon dioxideindustrial solid wastescoal-fired flue gas