Uncoated calcium carbonate is a versatile mineral that has a wide range of industrial and commercial applications. Some of the major or common uses of uncoated calcium carbonate include:

1. Paper manufacturing: Uncoated calcium carbonate is used as a filler and coating agent in the production of paper, improving its brightness, opacity, and printability.
2. Paints and coatings: It is used as a pigment extender and to improve the rheology, gloss, and durability of paints and coatings.
3. Plastics: Uncoated calcium carbonate is used as a filler to enhance the mechanical properties of plastic products, such as stiffness, impact resistance, and dimensional stability.
4. Rubber: It is used as a reinforcing agent in the production of rubber products, such as tires, belts, and hoses, to improve their strength and durability.
5. Construction: Uncoated calcium carbonate is used as a filler in concrete and mortar to improve their strength, durability, and workability.
6. Agriculture: It is used as a soil conditioner to neutralize acidic soils and provide essential nutrients to plants.
7. Food and pharmaceuticals: Uncoated calcium carbonate is used as a dietary supplement, an antacid, and a bulking agent in food and pharmaceutical products.

8. uncoated calcium carbonate is more commonly used for chalk manufacturing because it is less expensive and easier to work with. Uncoated calcium carbonate provides a fine, smooth texture that is ideal for writing and drawing, making it a popular choice for producing high-quality chalkboards and writing instruments.

   Coated calcium carbonate, on the other hand, is typically used in applications where improved surface properties, such as gloss, brightness, and printability, are required, such as in paper manufacturing, paints, and coatings

Overall, uncoated calcium carbonate is a highly versatile mineral that plays an essential role in many industrial and commercial applications.