SHI Rui ¹, TAO Chong ¹, TAN Zhenya ¹, LI Qinyu ¹, WU Yue ¹, JIANG Jiuxin ^{1, 2}

(1. Hubei Provincial Key Laboratory of Green Materials for Light Industry, Hubei University of Technology, Wuhan 430068, Hubei, China; 2. New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, Hubei University of Technology, Wuhan 430068, Hubei, China)

Abstract: Due to its low thermodynamic stability, it is difficult to synthesize vaterite phase of CaCO₃. The effect of milling time, milling speed and the weight ratio of milling ball to reactant on the polymorphs and the morphologies of CaCO₃, in absence of NaCl or KCl as diluter, was firstly studied. Amorphous CaCO₃ (ACC) was formed at the early reaction stage and at low milling speeds, while otherewise calcite is the only phase. Prolonging milling time, enhancing milling speed and increasing the weight ratio of milling ball to reactant are beneficial to the formation and crystallization of calcite. The effect of sodium dodecyl sulfonate (SDSN) and sodium hexametaphosphate (SHMP) on the polymorphs and the morphologies of CaCO₃ was then evaluated, indicating that both SHMP and SDSN can promote the formation of vaterite. The percentages of vaterite phase are 58.2 wt.% and 81.9 wt.%, when using SDSN and SHMP respectively.

Key words: CaCO₃; vaterite; high-energy milling method; additive