Magical calcium carbonate! How many of these 8 "secret uses" do you know?

Calcium carbonate is a super-excellent filler. It is white and pure, easy to color, has stable chemical properties, and is very cheap. The particle size and shape can be adjusted at will. With these advantages, it has long been successfully introduced into many industries such as rubber, plastic, plastic steel doors and windows, PVC cable materials, and advanced coatings. From building materials to food, from medicine to textiles, it can be found everywhere. But how many of the eight main "hidden uses" do you know?

High-value application of calcium carbonate

1. Conductive coatings: Light calcium carbonate has low cost and a wide range of raw materials. It is commonly used in polymer materials, but it is not conductive. Using it as a matrix to prepare CaCO₃-polyaniline (PANI)/SiO₂ conductive composite powder for conductive coatings can reduce costs, strengthen the mechanical strength of the coating, and give the coating conductivity and antistatic properties. SiO₂ coating can also improve the acid resistance of calcium carbonate.

2. Food and health: Food-grade calcium carbonate is widely used and can be used in calcium nutritional health foods, various calcium preparations, and foods such as chewing gum and chocolate. For example, the research and development of nano calcium carbonate with a specific surface area of 30m²/g can increase the calcium content of milk beverages and prevent precipitation; seafood sauce can improve the texture and extend the shelf life; calcium carbonate D3 chewable tablets are used for calcium supplementation and prevention and treatment of osteoporosis, with a calcium carbonate content of about 50%-75%.

3. Ceramics: Develop cubic calcium carbonate with uniform particle distribution, which can be used to make densified ceramics at a low temperature of 600℃. Nano calcium carbonate is also used in piezoelectric ceramics, and has a relatively good effect.

4. Engineering: Nano calcium carbonate prepared by the new double-layer modification technology of plastics is used in engineering plastics, which can produce high-white and heat-resistant engineering plastic products.

5. Lightweight fillers: Develop spherical shell-shaped lightweight (lightweight) fillers with a specific gravity of only 0.2-0.3cm/g. Compared with other balloon fillers, it is not easy to break and can reduce the specific gravity. It can be used in rubber, plastic and other industries.

6. Drug loading: (1) Liu Nianxing’s team prepared Pickering emulsion with heavy calcium carbonate and added sodium alginate to construct a pH-responsive emulsion system, which can be used as a nutrient or drug carrier, providing new ideas for the design of enteric preparations; (2) Zhu Lin’s team prepared petal-shaped calcium carbonate, which can efficiently load the anti-tumor drug doxorubicin hydrochloride (DOX). It has a good sustained release effect under weakly acidic conditions and has a specific inhibitory effect on tumor cells.

7. Water phosphorus removal: Studies have shown that the crystal phase and particle size of calcium carbonate significantly affect the phosphorus removal effect. When the calcite phase is the main phase, accompanied by a small amount of spherical nepheline phase, it is spherical and cubic, and the 60nm small particles are accumulated into 3-5um large particles with a rough surface, the treatment efficiency of phosphorus-containing water can reach 73%.

8. “Life, Optics, and Electricity”: Japan uses calcium carbonate with a purity of ≥99.5% in: (1) Life sciences: for example, calcium carbonate sintered bodies for artificial bone filling materials, and research on their suitability as bone transplant materials and cell support carriers; (2) Electronics: for example, ceramic capacitors; (3) Optics: for example, luminescent bodies.