Abstract: For high value-added utilization of carbide slag and sequestration of CO₂, spherical vaterite was prepared at atmospheric pressure using carbide slag as raw material and various additives. The effects of additive types, reaction temperature, impurities in carbide slag and reaction system on vaterite in calcium carbonate synthesis were investigated by X-ray diffraction, scanning electron microscope and fourier transform infrared spectroscopy. The results show that glycine and serine have significant effect on the formation of vaterite. The increase of reaction temperature is not conducive to the formation of vaterite. The impurities Al₂O₃ and SiO₂ in carbide slag induce Ca(OH)₂ mineralization CO₂ system to form calcite. Different reaction systems affect the crystal size of prepared vaterite, and the crystal size prepared by carbide slag-CO₂ system is the smallest. In the carbide slag-CO₂ reaction system at 15 ℃, monodisperse vaterite type CaCO₃ with rough protrusions on the surface can be prepared by adding glycine. The above results provide a simple method for preparing high value-added vaterite from alkaline industrial wastes such as carbide slag, and safely and effectively storing a large amount of CO₂ greenhouse gases.

Key words: carbide slag, vaterite, glycine, serine, carbon dioxide