Main Characteristics
· Chemical Composition
Its main component is calcium carbonate (CaCO₃) with a purity of 90%~99%, containing trace impurities such as magnesium carbonate (MgCO₃), silicon dioxide (SiO₂) and ferric oxide (Fe₂O₃).
· Physical Properties
1.Density: 2.6~2.9 g/cm³ (higher than light calcium carbonate at 2.4~2.6 g/cm³)
2.Whiteness: Over 90% (subject to raw material purity)
3.Particle size: Normally 0.5~45 μm (fineness adjustable via classification)
4.Oil absorption value: Relatively low (around 20~30 g/100g), presenting excellent filling performance
· Crystal Morphology
Most particles are irregular, retaining the hexagonal crystal system structure of calcite or marble.
· Production Processes
1.Raw Material Selection: High-purity calcite, marble or chalk.
2.Crushing: Coarse crushing into particles several centimeters in size.
3.Grinding: Fine grinding with Raymond mill, ball mill, vertical mill and other equipment.
4.Classification: Products of different fineness are obtained through air classification or mechanical classification.
5.Surface Treatment (Optional): Modified with coupling agents such as stearic acid and titanate to improve compatibility with polymers.
