Synergetic effects of initial NH4+ and Ca2+ concentration on the formation vaterite using steamed ammonia liquid waste as a direct carbonation

Vaterite-phase calcium carbonate (CaCO3) has many distinctive properties compared to calcite and aragonite-type polymorphs, but vaterite is typically difficult to form in a naturally occurring reaction system. In this investigation, the effects of initial NH4+ and Ca2+ concentrations on crystal structure, morphology, particle size, and vaterite content were systematically investigated. The obtained vaterite samples were characterized using powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and laser particle size analysis (LPSA) techniques. High concentrations of NH4+ and Ca2+ are both advantageous to the formation of vaterite, and high concentrations of NH4+ and Ca2+ play an evident synergistic role in the formation of single phase vaterite. On the basis of an analysis of the properties of the initial reaction system in the presence of varying concentrations of NH4+ and Ca2+, a potential mechanism NH4+ and Ca2+ for vaterite formation is revealed.