Mineralization of simulated flue gas to prepare CaCO3 whisker using suspended CaSO4

CaCO₃ whiskers were synthesized controllably by introducing simulated flue gas containing CO₂ and N₂ into a CaSO₄ suspension. The effects of solution pH, reaction temperature, and simulated flue gas on the formation of CaCO₃ whiskers were studied. The growth mechanism and growth model of CaCO₃ whiskers had also been provisionally recommended. The reaction product was characterized by scanning electron microscopy analysis, thermogravimetric analysis, and X-ray diffraction analysis. CaCO₃ whiskers with 97% purity were synthesized at pH 7.5, 80°C, 0.1 L/min CO₂ flow rate, and 16.7% CO₂ purity, with a length between 15 and 20 μm and an aspect ratio of about 12.