Sonochemical Synthesis of Vaterite-Type Calcium Carbonate Using Steamed Ammonia Liquid Waste without Additives

[Image: see text] Herein, metastable spheroidal vaterite calcium carbonate (CaCO(3)) was prepared using a simple ultrasound technique. The fabricated material comprises an irregular nanoparticle aggregate when steamed ammonia liquid waste, that is, (CaCl(2)) and (NH(4))(2)CO(3), is used as the raw material at atmospheric temperature, without any surfactants. The effects of ultrasound amplitude, probe immersion depth, and solution volume on particle properties were investigated. The obtained samples were identified and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and the Brunauer–Emmett–Teller technique. Our experiments show that the probe immersion depth and the reaction volume are the key parameters that impact the diameter size and size distribution of the fabricated spheroidal vaterite CaCO(3) particles. The ultrasound amplitude considerably affected the particle size and the specific surface area. A possible formation mechanism for pure vaterite is proposed herein, which suggests that simple vaterite CaCO(3) is formed owing to the special properties of steamed ammonia liquid waste and the synergistic effects of the ultrasonic system. This study may provide a new method for vaterite CaCO(3) synthesis.