Abstract
Calcium carbonate (CaCO(3)) whiskers are promising materials for the high-value utilization of calcium-based resources. Here, aragonite whiskers were synthesized at a carbonation temperature of 90 °C using carbide slag ammonium leachate as the calcium source and CO(2) as the precipitant. The effects of control agents, carbonation temperature, Ca(2+) solution feeding rate, CO(2) flow rate, and stirring speed on whisker morphology and aspect ratio were systematically investigated. Characterization via SEM and XRD revealed that the optimal conditions-carbonation temperature of 90 °C, Ca(2+) feeding rate of 1.2 mL∙min(-1), ethanol addition of 2 mL, CO(2) flow rate of 150 mL∙min(-1), and stirring speed of 300 rpm-yielded uniform CaCO(3) whiskers with an average length of ~10 μm, an aspect ratio of ~24, and an aragonite purity of 99.42%. TEM confirmed that the whiskers are single crystals growing preferentially along the [001] direction. Hydroxyl groups were found to suppress lateral growth on the (200) facet, favoring elongation along the c-axis and enabling high-aspect-ratio whisker formation. These findings provide useful guidance for the scalable synthesis and industrial application of aragonite whiskers.