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Product Overview
Calcium carbonate is an inorganic compound with the chemical formula CaCO₃. It is a key component of limestone, marble, and other materials. Typically found as white crystals, it is odorless, largely insoluble in water, and reacts with acids to release carbon dioxide. It's one of the most common substances on Earth, present in minerals like aragonite, calcite, chalk, limestone, marble, and travertine, and is also a major component of some animal bones or shells. Calcium carbonate is also an important building material with wide industrial applications.
Depending on the production method, calcium carbonate can be classified into ground calcium carbonate, precipitated calcium carbonate, colloidal calcium carbonate, and crystalline calcium carbonate. Based on the average particle diameter (d) of calcium carbonate powder, it can be classified into microfine calcium carbonate (d>5μm), micropowder calcium carbonate (1μm), and ultrafine calcium carbonate (0.02μm). Additionally, calcium carbonate can be divided into crystalline and amorphous forms based on the arrangement of atoms and ions. There is also nano-calcium carbonate.
Calcium Carbonate Production Process
Ground Calcium Carbonate
Ground calcium carbonate (commonly known as heavy calcium) is obtained by mechanically grinding natural calcite, limestone, chalk, shells, etc., using Raymond mills or other high-pressure mills.
Precipitated Calcium Carbonate
Precipitated calcium carbonate (commonly known as light calcium) is produced by calcining raw materials like limestone to create lime (primarily composed of calcium oxide) and carbon dioxide. The lime is then hydrated with water to form lime milk (mainly calcium hydroxide), and carbon dioxide is passed through the lime milk to precipitate calcium carbonate, which is then dehydrated, dried, and ground. Alternatively, it can be produced by reacting sodium carbonate with calcium chloride to precipitate calcium carbonate, followed by dehydration, drying, and grinding.
Colloidal Calcium Carbonate
Colloidal calcium carbonate, also known as activated calcium carbonate, modified calcium carbonate, surface-treated calcium carbonate, colloidal calcium carbonate, or simply active calcium, is produced by surface-modifying light calcium carbonate or ground calcium carbonate with surface modifiers. These modified calcium carbonates generally have reinforcing properties, commonly referred to as "activity," which is why modified calcium carbonate is often called active calcium carbonate.
Properties: White, fine, lightweight powder, with a fatty acid soap layer on the particle surface that gives CaCO₃ colloidal activation properties. Specific gravity is 1.99–2.01.
Crystalline Calcium Carbonate
Properties: Pure white, hexagonal crystalline powder. Bulk volume is 1.2–1.4 ml/g. Soluble in acid, nearly insoluble in water.
Nano Calcium Carbonate
Nano-calcium carbonate (ultrafine calcium carbonate) has good compatibility with resins in plastics and can effectively increase or adjust the rigidity, toughness, and bending strength of materials. It can also improve the rheological properties of plastic processing systems, lower plasticizing temperature, enhance product dimensional stability, heat resistance, and surface smoothness. In NR, BR, SBR, and other rubber systems, it mixes easily, disperses uniformly, softens the rubber, and enhances extrusion processing performance and mold flowability. It gives rubber products a smooth surface, high elongation, high tensile strength, low permanent deformation, good bending resistance, and high tear strength.
Calcium Carbonate: Benefits and Uses
Calcium Carbonate: Application Scenarios
Laboratory Uses:
- In the biological experiment "Extracting Pigments from Green Leaves," adding a small amount of calcium carbonate during grinding can prevent the pigments from being damaged.
- Calcium carbonate is used in the preparation of CaO, Ca(OH)₂, and NaOH:
- Calcium carbonate is calcined at high temperatures to produce calcium oxide and carbon dioxide. The reaction equation is: (The calcium oxide produced can be used as a desiccant). The prepared calcium oxide reacts with water to form calcium hydroxide: (Calcium hydroxide can react with sodium carbonate to prepare caustic soda:).
- Calcium carbonate reacts with hydrochloric acid (usually diluted hydrochloric acid) to produce carbon dioxide: CaCO₃ + 2HCl = CaCl₂ + CO₂↑ + H₂O (The calcium chloride solution produced can be used to standardize soap solutions).
Industrial Uses:
Calcium carbonate is an incredibly valuable resource with a wide range of applications. Limestone, as a commercial name for this mineral, has been widely used throughout human history due to its abundant distribution in nature and ease of acquisition. It has a long history as an essential building material. In modern industry, limestone is the primary raw material for producing cement, lime, and calcium carbide. It is an indispensable fluxing agent in the metallurgical industry. High-quality limestone, when ground to an ultra-fine powder, is extensively used in the manufacturing of products like paper, rubber, paint, coatings, pharmaceuticals, cosmetics, feed, sealants, adhesives, and polishes. According to incomplete statistics, the total consumption of limestone for cement production, construction materials, lime production, metallurgical flux, and ultra-fine calcium carbonate is in a ratio of 1:3. Limestone is a non-renewable resource. With continuous scientific and technological advancements and the development of nanotechnology, the application fields of limestone will further expand.
1. Application in Plastic Production:
Calcium carbonate is widely used as a filler in resins such as polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), acrylonitrile butadiene styrene (ABS), and others. Adding calcium carbonate can enhance and improve certain properties of plastic products, thus expanding their application scope. In plastic processing, it can reduce resin shrinkage, improve flow properties, and control viscosity. Additionally, it can:
- Improve the dimensional stability of plastic products.
- Enhance the hardness and rigidity of plastic products.
- Improve the processing performance of plastics.
- Increase the heat resistance of plastic products.
- Improve the light diffusion properties of plastics.
- Provide certain special properties to the products.
- Reduce the cost of plastic products.
2. Application in the Food Industry:
In the food industry, it can be used as an additive. For example, it can be used as a feed additive, with a calcium content of over 55.6% and no harmful components. It can be used as a calcium supplement, with an absorption rate of up to 39%, second only to calcium citrate. It is soluble in stomach acid and has become one of the most widely used forms of calcium supplements in various dosage forms.
3. Application in the Construction Industry:
It can be used as a raw material in plastic factories, rubber factories, paint factories, and waterproof materials factories, as well as for interior and exterior wall painting. It is characterized by high purity, high whiteness, non-toxic, odorless, low oil absorption, and low hardness. Marble is also an important building material used in house construction.
4. Application in the Chemical Manufacturing Industry:
- 350 to 400 mesh: Used in the manufacture of panels, drainage pipes, and chemicals. Whiteness above 93 degrees.
- 400 to 600 mesh: Used in toothpaste, soap. Whiteness above 94 degrees.
- 800 mesh: Used in rubber, cables, PVC. Whiteness above 94 degrees.
- Can also be used in the manufacture of optical neodymium glass raw materials, among others.
Nutritional Supplement:
Most calcium tablets on the market have calcium carbonate as their main ingredient. Calcium carbonate should be taken with meals. Because it contains carbonate, it easily produces carbon dioxide in acidic environments, making it unsuitable for people with poor stomach acid secretion or those using acid inhibitors.
Packaging and Storage of Calcium Carbonate
Storage Conditions: This product should be sealed, protected from light, and stored in a dry, cool, and well-ventilated place, avoiding high temperatures.
Packaging Method: Bulk: 25kg/paper drum; Sample: 1kg/aluminum foil bag. Custom packaging is available upon request.
Transportation Method: Courier or logistics. Domestic courier delivery within three days, logistics delivery within five days. Pricing generally includes domestic shipping costs.
Shelf Life: Two years.
