Calcium carbonate reacts with acids, decomposes at high temperatures, and reacts with water containing carbon dioxide; these properties make it highly useful in both laboratory and industrial settings.
1. Pulverize calcium oxide powder to a particle size of 10–50 μm, slake it in hot water, dilute with water, and stir at high speed to prepare a calcium hydroxide suspension with a mass percentage concentration of 1–5%;
2. Subject the suspension to carbonation by introducing a CO₂-containing gas at 15–25°C-maintaining the CO₂ content in the gas between 20% and 35%-until the pH reaches 6–7, thereby obtaining a calcium carbonate slurry;
3. Heat and dissolve an aromatic polyester polyol, then mix it uniformly with an aluminate coupling agent using ultrasonic agitation to prepare a surface treatment agent solution;
4. Add the surface treatment agent solution-in an amount equal to 0.7–2.0% of the calcium carbonate slurry's weight-to the calcium carbonate slurry, stir well, and perform a coating treatment for 0.5–2 hours to obtain a surface-modified calcium carbonate slurry;
5. Feed the surface-modified calcium carbonate slurry and a compressed gas mixture of CO₂ and nitrogen separately through a two-fluid atomizing nozzle; the slurry is dispersed into micron-scale droplets by the high-pressure CO₂/nitrogen mixture while simultaneously undergoing a carbonation reaction, and is rapidly dried by a hot gas stream, directly yielding the active light calcium carbonate powder of the present invention.