Preparation of Highly Dispersed CaCO3 Nanoparticles in a Novel Membrane Dispersion Microreactor by a Chemical Coprecipitation Process

A chemical coprecipitation method has been developed for the preparation of CaCO3 nanoparticles using a novel membrane dispersion microreactor with calcium chloride, sodium carbonate, and calcium hydroxide as the reagents. Compared with the traditional coprecipitation process in a stirred tank reactor, a novel membrane dispersion microreactor has been developed, which makes it easier to control the crystal size. The effects of supersaturation, reaction time, feed flow rate, and reaction temperature on the size of CaCO3 particles have been investigated. Synthesized CaCO3 products are characterized by TGA, FT-IR, XRD, SEM, TEM, and BET. The results show that the crystal size of the prepared CaCO3 in this novel procedure reaches 18.8 nm, and the surface area reaches 45.94 m2/g. Compared with traditional methods, the membrane dispersed process is of important application value because of its smaller mean particle size, lower cost, and higher efficiency. Furthermore, the application scope is more extensive because of no additional additives.