Continuous manufacturing of microsized vaterite using CO2 supersaturated water in a semi-pilot plant

• Homogenizer-assisted synthesis of microspherical vaterite crystals was achieved. • Semi-pilot scale PCC production was demonstrated using CO 2 supersaturated water. • PCC conversion efficiencies of 99.4–99.5% were achieved under stable operation. • Vaterite constitutes the dominant crystalline phase, with a minor calcite phase. • Sustainable CO 2 mineralization shows the potential of scalable carbon utilization. Vaterite, a metastable polymorph of precipitated calcium carbonate (PCC), is highly desirable for diverse applications owing to its large specific surface area, high porosity, and high dispersibility. Nevertheless, achieving large-scale and continuous production of uniform vaterite particles remains a significant challenge. In this study, we present a novel semi-pilot scale process that enables stable and uniform synthesis of microsized vaterite through the use of CO 2 supersaturated water, thereby overcoming the limitations of conventional batch methods. This study demonstrates the controlled crystallization of uniformly microsized spherical vaterite crystals with median particle diameters between 4.7 and 5.3 μm. The synthesis of vaterite is demonstrated in jar tests using a homogenizer, followed by the successful scale-up to the semi-pilot plant employing CO 2 supersaturated water produced by the direct dissolution of gaseous CO 2 into water. The process achieves high PCC conversion efficiency of 99.4–99.5 %. Scanning electron microscopy and X-ray diffraction spectroscopy confirmed the dominance of the vaterite, with a minor calcite. These findings demonstrate a scalable, water-compatible route for PCC production via CO 2 supersaturated water, highlighting its potential integration into sustainable carbon utilization technologies. This approach offers a promising pathway for the industrial-scale synthesis of microsized vaterite with controlled morphology and phase purity.