Uncoated Calcium Carbonate: Properties, Applications, and Industrial Uses
Introduction to Uncoated Calcium Carbonate
Uncoated calcium carbonate (CaCO₃) is the natural, untreated form of this widely used mineral filler. Unlike coated calcium carbonate, it has no surface modifications (such as stearic acid or silane treatments), making it more cost-effective while retaining its fundamental chemical and physical properties. It is available in two primary forms:
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- Ground Calcium Carbonate (GCC) – Milled from natural limestone, marble, or chalk.
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- Precipitated Calcium Carbonate (PCC) – Synthesized chemically for finer particle size and higher purity.
Uncoated calcium carbonate is widely used in industries where surface modification is unnecessary or where natural mineral properties are preferred.
Key Properties of Uncoated Calcium Carbonate
1. Physical & Chemical Characteristics
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- High Whiteness & Brightness (90-98% reflectance)
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- Particle Size Range:
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- GCC: 1–50 microns (coarse to fine)
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- PCC: 0.1–3 microns (ultra-fine)
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- High Purity (≥98% CaCO₃ in premium grades)
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- Alkaline Nature (pH ~9–10)
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- Low Oil Absorption (compared to coated grades)
2. Advantages Over Coated Calcium Carbonate
Lower Cost Higher Bulk Density Wider pH Compatibility Natural Mineral Properties
3. Limitations
Poor Polymer Compatibility Higher Viscosity in Melt Processing Moisture Sensitivity
Industrial Applications of Uncoated Calcium Carbonate
1. Paper Industry (Major Consumer)
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- Filler in Paper Coating & Bulk
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- Cost Reduction
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- PCC Preferred
2. Plastics & Polymers
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- Filler in PVC, PP, PE, and ABS
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- Used in Rigid PVC Pipes, Profiles, and Sheets
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- Thermoset Composites
3. Paints & Coatings
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- Extender Pigment
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- Matting Agent
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- Low-Cost Filler
4. Construction Materials
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- Cement & Concrete Additive
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- Asphalt Filler
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- Tile Adhesives & Sealants
5. Rubber Industry
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- Semi-Reinforcing Filler
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- Used in Tires, Belts, and Footwear
6. Food & Pharmaceuticals
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- Food-Grade CaCO₃ (E170)
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- Pharmaceutical Excipient
7. Environmental & Agricultural Uses
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- Soil Conditioner
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- Flue Gas Desulfurization (FGD)
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- Water Treatment
| Product | Median Particle size D50 (µm) | Top Cut D98 ( µm) | Particles under 2µm | Treated | Data Sheet |
| Mach 70 | 1.40 | 5.0 | 70% | x | Mach 70 |
| Mach 60 | 1.60 | 6.0 | 60% | x | Mach 60 |
| Mach 50 | 2.0 | 8.0 | 50% | x | Mach 50 |
| Mach 40 | 2.70 | 10 | 40% | x | Mach 40 |
| Mach 1 | 4.0 | 15 | 25% | x | Mach 1 |
| Mach 2 | 4.50 | 20 | 20% | x | Mach 2 |
| Mach 3 | 5.80 | 30 | 15% | x | Mach 3 |
| Mach 4 | 7.0 | 40 | — | x | Mach 4 |