Light calcium carbonate production equipment and processing technology

Light calcium carbonate, also known as precipitated calcium carbonate (PCC), is a widely used industrial mineral with applications in industries such as paint, plastic, rubber, and paper. Production equipment and processing technology for light calcium carbonate involve several stages, including mining, grinding, classification, and purification. Here is an overview of the equipment and technology involved:

1. Mining:

Calcium carbonate deposits are typically mined from underground or surface mines. The most common mining method is surface mining, involving the use of excavators, dump trucks, and crushers to extract the ore.

2. Crushing and grinding:

After mining, the calcium carbonate ore is crushed and ground to a fine powder. Crushing equipment such as jaw crushers and impact crushers are used to break the ore into smaller particles. Then, grinding equipment like ball mills or roller mills is used to further reduce the particle size.

3. Classification:

The ground calcium carbonate powder is subjected to classification to separate particles of different sizes. Classification equipment like air classifiers, hydrocyclones, or vibrating screens is used for this purpose. The coarser particles are recycled back to the grinding process, while the finer particles proceed to the next stage.

4. Purification:

The calcium carbonate powder contains impurities that need to be removed to achieve high purity. Purification processes involve chemical treatment or physical separation methods such as flotation, magnetic separation, or gravity separation. These techniques help remove iron, silica, and other impurities from the calcium carbonate powder.

5. Drying and calcining:

After purification, the calcium carbonate powder is dried to reduce moisture content and improve flowability. Drying equipment like rotary dryers or fluidized-bed dryers is used for this purpose. In some cases, calcining (heating the calcium carbonate powder to a high temperature) is also required to adjust the particle size and improve the physical properties of the final product.

6. Grinding and dispersion:

The dried and calcined calcium carbonate powder is further ground and dispersed in water to form a slurry. Grinding equipment like wet ball mills or horizontal sand mills is used for this purpose. The slurry contains fine calcium carbonate particles suspended in water.

7. Precipitation:

The slurry is treated with a solution of lime or sodium carbonate to cause the calcium carbonate particles to precipitate. This process involves adjusting the pH of the slurry and controlling the precipitation rate to ensure uniform particle size and low water content.

8. Filtering and drying:

After precipitation, the calcium carbonate particles are filtered from the liquid phase. Filter presses or vacuum filters are used for this purpose. The filtered calcium carbonate is then dried to achieve the desired final product moisture content.

9. Packaging and storage:

The dried calcium carbonate powder is packed into bags or containers for storage and transportation. Modern packaging equipment ensures the integrity of the product and prevents contamination during storage and handling.

Light calcium carbonate production equipment and processing technology have been continuously improved to meet the growing demand for high-quality products. The equipment and technology listed above provide a robust and efficient method for converting calcium carbonate ore into highly pure and useful products.