Q: What minerals are commonly used in papermaking?

A: Several minerals are widely used in the papermaking industry to improve paper quality, brightness, and printability. The most common ones include:

1. Calcium Carbonate (CaCO₃) – Enhances brightness, opacity, and smoothness; often used in coated and uncoated papers.

2. Kaolin (China Clay) – Improves paper gloss and smoothness; commonly used in coating layers.

3. Talc – Reduces pitch problems, improves surface smoothness, and enhances filler retention.

4. Gypsum (Calcium Sulfate) – Sometimes used in specialty papers for opacity and printability.

5. Titanium Dioxide (TiO₂) – Provides high whiteness and opacity, mainly for high-grade coated papers.

6. Dolomite – Improves brightness and reduces production costs as a filler.

7. Ground Calcium Phosphate – Used in specialty applications for surface properties.

Q: What is the main function of these minerals in paper?

A: They improve optical properties (brightness, whiteness, opacity), physical properties (smoothness, printability), and reduce production costs by partially replacing pulp fibers.

Q: Are these minerals suitable for all types of paper?

A: Different minerals are chosen based on the paper type. For example, kaolin is preferred for coated papers, while calcium carbonate is common in newsprint and high-volume uncoated papers.

Stones and Minerals grinding machine