Taking up more than 4% of the Earth’s crust, it is unexaggerated to say that calcium carbonate is one of the most vital substances with human’s production activities. This material is widely applied in many fields such as paper, paints, coating, healthcare,…and most importantly, plastic industry. In this article, let’s discover the most common applications of calcium carbonate. 

Calcium carbonate might be one of the most well-known substances to humans as most of us encounter its common application – chalk. Nevertheless, it is just one of tons of uses of calcium carbonate as this material is widely applied in various industries such as construction, plastic, paper and even healthcare.

1. Calcium carbonate – What is it?

Calcium carbonate (formula CaCO3) is a substance commonly found in rocks under 3 main forms: chalk, limestone and marble. Though they may share some common in terms of chemical formula, they can easily be distinguished by certain identities such as whiteness, purity, thickness and homogeneity.  Also, this material is the main component of eggshells, snail shells and seashells. 

Thanks to its affordability and outstanding benefits, calcium carbonate can be used in many important applications. Most of the calcium carbonate applied in industry is exploited from mines or quarries. Base on properties and processing technology, calcium carbonate is divided into two main types: 

• Ground calcium carbonate (GCC) is produced by crushing limestone into particles, which are then classified based on their sizes. The output material has a powdery-like form. GCC is widely used in many industries, especially in pharmaceutical applications

• Precipitated calcium carbonate (PCC) has a more complex manufacturing process compared with that of GCC. Raw calcium carbonate extracted from marble is first calcified under high temperature (1000 Degree Celcius). Calcium oxide (quick lime) obtained from this phase is subsequently hydrated before being passed by carbon dioxide and dried to create precipitated calcium carbonate. PCC has a very fine and controlled particle size, which is consistently 2 microns in diameter, making it an appropriate choice for paper production.

2. Why calcium carbonate?

Calcium carbonate is widely used in many industries thanks to its outstanding advantages:

• CaCO3’s natural whiteness helps products achieve natural whiteness without any bleaching agents, whitening agents or other pigments, which saves plastic enterprises a large amount of production cost. 

• Calcium carbonate is a mineral substance with abundant reserves in nature. Their availability together with simple processing make it relatively affordable. Manufacturers can use calcium carbonate in bulk without worrying about cost.

• Another plus point of calcium carbonate is the inertness. The use of CaCO3 powder will not change the specific properties of plastic resins, thus plastic enterprises can use them to partly replace primary plastic to save production cost.  

• Some outstanding properties of calcium carbonate include excellent thermal resistance, environmental friendliness, anti evaporation and temperature reduction ability. It also assists in increasing the hardness, glossiness and printability of plastic surfaces, which significantly improves the competitiveness of plastic products. 

3. Common uses of calcium carbonate

The applications of calcium carbonate ranges from construction, manufacturing to healthcare industry. These following are amongst the most popular applications of calcium carbonate in our daily life. 

Plastic applications

There is no denying that the application of calcium carbonate as a plastic filler has really revolutionized this industry. Generally, calcium carbonate filler is the combination of plastic resin (approximately 30%) and CaCO3 powder (70% and above depending on specific products). 

The use of calcium carbonate in plastic products has its root in the heavy dependence of plastic enterprises on plastic resins. For centuries, plastic manufacturers heavily depended on primary resins until the use of calcium carbonate filler was figured out. Thanks to its affordability and outstanding properties, calcium carbonate filler can take up to 70% by weight of the plastic products. Not only does it save a significant amount of production expenses, calcium carbonate filler also enhances certain properties of end-products such as rigidity, glossiness and brightness. For example, PVC cables can use calcium carbonate at loadings of up to 70 phr (parts per hundred parts of resin) to improve mechanical properties (tensile strength and elongation) and electrical properties (volume resistivity). Polypropylene compounds are often filled with calcium carbonate filler with the proportion of 20–40% to increase rigidity.

Construction applications

Calcium carbonate largely contributes to the sustainability of our infrastructures. It can act as both building material (marble) and cement’s ingredient. When being added to concrete, calcium carbonate improves self-compacting properties, thus helping end-products work more efficiently, increasing strength and smoothing the product’s surface. Besides, it assists in making mortar, which is used in bonding bricks, concrete blocks, stones, roofing shingles, rubber compounds, and tiles. When it comes to asphalt, calcium carbonate plays as a multi-purpose filler/anti-strip agent which is added to hot rolled asphalt to improve the resistance of the mixture and provide a consistent material that is easier to work with.

What’s special about calcium carbonate is that its decomposition can lead to the formation of carbon dioxide and lime, an indispensable component in making steel, glass and paper. 

Paper and paints applications

Thanks to its natural white color and light scattering properties, calcium carbonate is widely used as a useful filler in the paper industry to enhance opaque paper’s brightness as well as reducing production cost. Filler is added at the wet-end of the paper making machine to help the outputs brighter and smoother. Furthermore, this material also accounts for as much as 30% by weight in paints. As an extender, calcium carbonate can represent as much as 30% by weight in paints (usually chalk or marble).  

Health and environmental applications

Calcium carbonate is widely used as an effective dietary calcium supplement, antacid, phosphate binder, or base material for medicinal tablets. It is also found in many products such as baking powder, toothpaste, dry-mix dessert mixes, dough, and wine. Besides, this material is also an active ingredient in agricultural lime, and is used in animal feed. 

Thanks to its antacid properties, calcium carbonate can be also used in industrial settings to neutralize acidic conditions in both soil and water. In The United States, calcium carbonate powder has been currently sprinkled onto acidic waterways to neutralize noxious acids. Scandinavia and Scotland also leverage calcium carbonate in this manner. Limestone deposits are used in the treatment of unplanted areas surrounding affected lakes and water bodies.

4. PolyFill calcium carbonate filler

After over 5 years of development, PolyFill calcium carbonate filler has been currently available in over 80 countries. Being made of high-quality Vietnamese CaCO3 powder and plastic resins with an exact formula customized for each customer, our filler masterbatch can surely meet all of the strictest requirements. There are various types of calcium carbonate fillers such as PE filler masterbatch, PP filler masterbatch, Transparent filler masterbatch,…

For further information and consultation, contact us HERE!