Key Technical Indicators for Ultrafine Calcium Carbonate Selection
Ultrafine calcium carbonate (UFCC) performance hinges on four core parameters: particle size, specific surface area, crystal morphology, and oil absorption value. While other metrics matter, these determine functional suitability across industries.
1. Particle Size & Specific Surface Area
Primary particles: Must achieve 0.02–0.1μm range to qualify as "ultrafine."
Agglomeration risk: TEM imaging shows primary particles, but BET analysis reveals true surface area after secondary particle dispersion.
Measurement pitfall: Traditional sedimentation methods fail due to crystal shape variability.
Pro tip: Combine TEM and BET testing for accurate size/dispersion assessment.
2. Crystal Morphology Matters
| Application | Optimal Crystal Shape | Key Benefit |
|---|---|---|
| Plastics | Cubic/Spherical | Reduces PVC whitening, improves gloss & impact strength |
| Rubber | Chain-like | Enhances tensile strength via 3D network bonding |
| Inks | Cubic | Maximizes gloss and flow in resin-based systems |
| Paper Coating | Lamellar/Cubic | Boosts opacity and ink absorption (0.1–1μm particles) |
3. Oil Absorption Value Control
Critical for: Plastics (plasticizer consumption), coatings/inks (viscosity).
Key factors: Particle size dispersion > nominal size. Agglomerated particles render low absorption values meaningless.
4. Main Content (CaO) Flexibility
Tolerable range: 90–95% CaO acceptable for most functional filler uses.
Controlled impurities: Strict limits on Fe/Mn (<0.02%) to prevent resin degradation; manage Si/Al/Mg for whiteness.
Industrial Strategy:
Specialization: Develop application-specific UFCC grades (e.g., chain-like for tires, cubic for PVC pipes).
Avoid "one-size-fits-all": Unified standards fail – tailor particle metrics to end-use (e.g., 0.072μm spheres for cable insulation vs. 0.1μm cubes for films).
Source: Jinfeng Mining. Technical data subject to variation. Content removal available upon request.