Precipitation Process of CaCO3 from Natural Limestone for Functional Materials

Area of Science:

• Materials Science
• Chemical Engineering
• Inorganic Chemistry

Background:

• Precipitated calcium carbonate (CaCO3) is a widely used material in various industries.
• Controlling the morphology and particle size of CaCO3 is crucial for optimizing its performance in specific applications.
• Existing production methods often lack the precision to yield desired CaCO3 characteristics.

Purpose of the Study:

• To investigate and report on the production of precipitated CaCO3 with diverse morphologies and particle sizes.
• To evaluate the effectiveness of different carbonation techniques in controlling CaCO3 precipitation.
• To establish alternative routes for producing tailored CaCO3 particles from natural limestone.

Main Methods:

• Simple CO2 gas bubbling into calcium hydroxide (Ca(OH)2) solution.
• Modified bubbling technique involving interrupted gas flow and varying stirring speeds.
• Rapid mixing of solutions at controlled temperatures.

Main Results:

• The simple bubbling method yielded up to 100% calcite particles at intermediate temperatures.
• The modified bubbling technique produced 99% aragonite particles at higher temperatures.
• Rapid mixing produced 95% spherical vaterite particles with porous structures at low temperatures.

Conclusions:

• The choice of carbonation method, reaction temperature, pH, solution concentration, and CO2 flow rate significantly influences CaCO3 morphology and particle size.
• These methods provide adaptable pathways for synthesizing precipitated CaCO3 with specific characteristics.
• The produced CaCO3 particles have potential for diverse industrial applications requiring tailored properties.