Industry grade Food grade 99% Calcium phosphate CAS 7758-87-4/12167-74-7 TCP

What is Tricalcium Phosphate? How does it work?

Tricalcium phosphate, or tricalcium orthophosphate, E341(iii), Ca3(PO4)2, is a calcium salt of phosphoric acid. It is a white crystalline powder, odorless and of low solubility in water. It is a principal inorganic constituent of human bones and teeth (as hydroxyapatite) and occurs naturally in milk and in the bones of vertebrates. Industrywide it's a flux in ceramic glazes, an important raw material in bone china, a source of calcium and phosphorus in phosphate fertilizers and animal feed and a base material for rust-preventive pigments in coatings. In the food industry, it is used as an anti-caking agent for table salt and a carrier for calcium supplementation.

Basic information Chemical formula Ca3(PO4)2 (molecular weight 310.18); CAS number 7758-87-4 (EC 231-840-8), $\beta$ crystal form also has CAS 12167-74-7; or obtained by calcination after the metathesis precipitation of soluble phosphate and calcium salt, or by processing phosphate rock; natural phosphate rock (phosphate rock) is the main mineral source, with large production in Morocco, Israel, Egypt, the Kola Peninsula of Russia and other places; naturally found in milk, bones and teeth and some meteorite minerals (Tuite).

It is a white, odorless powder, slightly soluble in water (extremely low solubility, approximately 0.002 g/100 mL) and insoluble in ethanol. The relative density is approximately 3.14, melting point is approximately 1670℃. The powder has fine particle size, large specific surface area and good flowability. Chemically, it is a calcium orthophosphate salt, weakly alkaline, and can react with acids to form soluble calcium dihydrogen phosphate, etc.; at high temperatures it can be converted into calcium pyrophosphate . It is used as a calcium source and flux in high-temperature systems such as ceramic firing and glass melting, and as a source of calcium and phosphorus in biological and food systems . It is chemically stable and very safe (its use in food is permitted by FAO/WHO as necessary for production).

From the perspective of mechanism of action,Tricalcium phosphate has multiple functions due to its high temperature fluxing properties, dual calcium and phosphorus supply capabilities, fine powder adsorption properties, weak alkalinity, moderate hardness and biological activity. The mechanisms of action in different applications are:

1. High temperature fluxing process

In tricalcium phosphate, CaO is a network modifier and fluxing component in the high temperature firing/melting system, it lowers the eutectic point and firing/melting temperature of the system, enhances the formation of liquid phase, and improves the density of the green body and the quality of the glaze.

2. Mechanism of calcium and phosphorus supply in nutrition

Tricalcium phosphate provides bioavailable calcium and available phosphorus (calcium to phosphorus ratio approximately 1.5:1, close to bone stoichiometry) and is involved in calcium and phosphorus metabolism processes in crops, livestock and humans including bones, teeth, roots and eggshells.

3.Anti-knot mechanism

Tricalcium phosphate fine powder evenly covers the surface of crystal particles like salt and sugar, adsorbing and isolating moisture, preventing bridging and adhesion between crystals, and keeping powdered food loose and fluid.

4. Passivation and anti-rust mechanism

The phosphate ions chemically react with the metal surface and form a dense phosphate passivation film that separates water and oxygen and retards the corrosion of steel. This explains the activity of anti-rust pigments with phosphates.

5.Mechanism of remineralization of tooth enamel

Functional tricalcium phosphate (fTCP) slowly releases calcium and phosphorus ions in the oral cavity, providing remineralization materials for tooth enamel, helping repair early caries lesions, and working synergistically with fluoride for caries prevention.

6.Mechanism of adsorption defluorination

Tricalcium phosphate removes excess fluoride from drinking water by adsorption and ion exchange to form insoluble fluorapatite with fluoride ions in water.

7. Non-reactive filling process

Tricalcium phosphate is chemically inert, high in whiteness, fine in particle size and moderate in density. As a filler, it can improve the rigidity of products, improve surface quality and reduce costs.

Summarize, tricalcium phosphate is a versatile component that spans across industry and people's lives, participating in the firing of ceramics and glass as a high-temperature flux, supporting agricultural feed and calcium-supplemented foods with its calcium and phosphorus supply, and serving coatings and water treatment with its passivation and adsorption capabilities, thus permeating the entire chain of building materials, agriculture, food, oral care, and health products.

What are the uses of Tricalcium Phosphate?

Tricalcium phosphate has a multitude of applications in ceramics, glass, agriculture, animal feed, plastics and rubber, coatings, surface treatment, water treatment, refractories, food processing, nutritional fortification, baking, dairy products, oral care and health products as shown below:

1. Ceramic glazes and body fluxes (the major application in the ceramics industry)

Application areas： Architectural ceramics, sanitary ceramics and daily-use ceramics

Related Products: ceramic tile glazes, sanitary ware glazes, ceramic colorant bases, body reinforcing agents, low temperature fast firing fluxes, art ceramic glazes, glazed tile glazes, etc.

Why it works for this purpose: In tricalcium phosphate, calcium oxide is a fluxing component during firing and lowers the glaze eutectic point, promotes the formation of the liquid phase, improves glaze gloss, whiteness and smoothness, and increases the body density and strength.

2. Bone china raw materials (used mostly in everyday ceramics).

Application areas： Bone china products.

Related Products:  bone china tableware (bowls, plates, coffee cups), bone china tea sets, bone china decorative crafts, bone china gifts, high-end hotel and restaurant porcelain, artistic bone china sculpture, etc.

Why it works for this purpose: The core raw material of bone china is tricalcium phosphate (artificial calcium phosphate). At high temperature it forms a glassy phase with kaolin and feldspar, giving bone china a translucent texture, high whiteness and good mechanical strength. This glassy phase is an essential part in the manufacture of bone china.

3. Fluxing and clarifying agents for glass and enamel (glass industry)

Application areas： glass and enamel industry.

Related Products: Flat glass batches, bottle and jar glass, glassware, glass fiber, enamel glaze, enamel base and top glazes, optical glass batches, etc.

Why it works for this purpose: Tricalcium phosphate provides calcium oxide as a network modifier in glass melting, lowering the melting temperature and viscosity, assisting in clarification and homogenization, and improving the water resistance of glass. In enamel, it acts as a flux to improve glaze leveling and adhesion.

4. Phosphate Fertilizers and Soil Conditioners (main use in agriculture)

Application areas：Fertilizer and agriculture industry.

Related Products: Raw materials of calcium magnesium phosphate fertilizer, Compound fertilizer ingredients, Phosphate fertilizer additives, Soil conditioners, Acidic soil amendment, Fertilizer for fruit trees and field crops, Slow release fertilizer coating materials, etc.

Why it works for this purpose: Tricalcium phosphate supplies available phosphorus (P2O5) and calcium, encouraging crop root development, flower and fruit formation, and stress resistance. It has weak alkalinity and can neutralize acidic soils, so it is commonly used as a source of calcium and phosphorus in phosphate fertilizer systems and soil improvement.

5.Calcium and phosphorus feed additives (Feed industry sector)

Application areas：Feed industry.

Related Products: Compound feed for livestock and poultry, Premixed feed, Calcium and phosphorus additives for pig, cattle and sheep feed, Poultry egg production feed (eggshell formation), Aquatic feed, Pet food calcium and phosphorus supplements, Feed grade calcium phosphate, etc.

Why it works for this purpose: Tricalcium phosphate supplies bioavailable calcium and phosphorus to maintain the balance of calcium and phosphorus metabolism, bone development in livestock and poultry, and the formation of eggshells. It is a common inorganic raw material used for calcium and phosphorus supplementation in feeds.

6. Fillers for plastics and rubber (polymeric materials field)

Application areas: Industry of plastics and rubber.

Related Products:  Polypropylene (PP) filler masterbatch, polyethylene (PE) products, PVC product fillers, rubber seals, rubber shoe materials, wire and cable sheathing materials, modified plastic reinforcing fillers etc.

Why it works for this purpose: Tricalcium phosphate is chemically inert, high whiteness, fine particle size and moderate density. It is useful as a filler for improving the rigidity, dimensional stability and surface whiteness of plastic and rubber products with a reduction in production costs.

7. Anti-corrosive pigments and coating extenders (coat industry)

Application areas：Industrial coatings, anti-corrosion coatings.

Related Products: Marine anti-rust primer, Bridge steel structure anti-corrosion coating, Container coating, Automobile chassis coating, Building steel structure anti-rust paint, Phosphate anti-rust pigment, Water-based anti-corrosion coating, etc.

Why it works for this purpose:Tricalcium phosphate produces phosphate ions, which react with steel surface to form a dense passivation film, stopping water and oxygen corrosion. It is the basic material for phosphate environment-friendly anti-rust pigments to replace the traditional lead-chromium anti-rust pigments.

8. Field of surface treatment Material for polishing and grinding

Application areas：Metal process, surface treatment.

Related Products: Metal polishing paste, aluminum and copper soft metal polishing agent, jewelry polishing powder, optical component polishing material, stainless steel surface treatment abrasive, eyeglasses lens polishing agent, precision parts polishing medium, etc.

Why it works for this purpose: Tricalcium phosphate is a soft abrasive with a moderate Mohs hardness that can remove oxide layers and micro-defects from workpiece surfaces without scratching the substrate. This makes it suitable for fine polishing of soft metals, jewelry and optical components.

9. Drinking water defluorinator (field of water treatment)

Application areas： Purification and water treatment.

Related Products: Drinking water defluoridation filter media in high-fluoride areas, defluoridation water purifier filter cartridges, bone char defluoridating agents, packing materials for centralized water supply defluoridation devices, industrial fluoride-containing wastewater treatment agents, fluoride-containing wastewater adsorption materials, etc.

Why it works for this purpose: Tricalcium phosphate reacts with fluoride ions in water by adsorption and ion exchange to form insoluble fluorapatite that can remove excess fluoride to drinking water standards. It is a commonly used material in high fluoride water treatment and purifying equipment for defluoridation.

10.Binders for refractories (refractory materials)

Application areas: Refractory materials and industrial high temperature areas.

Related Products: Phosphate bonded refractory castables, Monolithic refractories, Kiln lining materials, High temperature furnace repair materials, Ceramic kiln furniture, Refractory bricks for glass kiln walls etc.

Why it works for this purpose: Tricalcium phosphate reacts with the components of the system, creating a phosphate-bonded phase at high temperatures, which improves the bonding strength, thermal shock stability and erosion resistance of the refractory material. This is suitable for lining high-temperature equipment such as kilns and glass melting furnaces.

11. Salt and anti-caking agents for powdered foods (Major application in food processing)

Application areas : Food processing.

Related Products : Salt (Iodized salt, Low sodium salt, Sea salt), Powdered sugar, Granulated sugar, Spice powders (Chili powder, Pepper powder), Compound seasoning powders, Non-Dairy creamer (Coffee creamer), Milk powder, Solid beverage powders, Baking premixes, Chicken essence/MSG powder etc.

Why it works for this purpose:Tricalcium phosphate (E341(iii)) fine powder coats the surface of crystal particles, adsorbs and isolates moisture and prevents crystal bridging, keeping powdered foods loose and flowing without clumping for a long time. It is a classic anti-caking agent for food.

12. Calcium Fortifiers (Core Use in Fortified Foods and Infant Formula)

Application areas： Infant formulas, fortified foods.

Related Products: include baby formula, children’s growth formula, senior’s milk powder, calcium-fortified milk and yogurt, breakfast cereals, calcium-fortified drinks and soy milk, fortified biscuits, nutritional rice cereals, sports nutrition foods, etc.

Why it works for this purpose: Tricalcium phosphate provides bioavailable calcium and phosphate in a calcium to phosphorus ratio close to bone stoichiometry. It steadily releases calcium into food and supports bone and teeth development and maintenance and is a common calcium source in calcium-fortified foods.

13.Baking food processing aids (baking food industry)

Application areas: Bakery Industry.

Related Products: Baking powder ingredients, cake premixes, bread improvers, biscuit dough conditioners, frozen dough, puffed foods, pastry powders, etc.

Why it works for this purpose: Tricalcium phosphate is used as a buffering acid and source of calcium in baking systems. It is used with acidic salts to control the fermentation process, to stabilize the pH and texture of the dough and to improve the leavening and shape retention of the product.

14.Dairy products stabilizers and processing aids (dairy industry)

Application areas : Dairy Processing

Related Products: Cheese, processed cheese, ice cream, condensed milk, whipped cream, dairy drinks, yogurt stabilization systems, whey products, etc.

Why it works for this purpose: Tricalcium phosphate and its phosphate system act as calcium balancers and buffers in dairy products, keeping the structure of casein micelles, improving emulsification and water retention, preventing precipitation and stratification, and meanwhile supplementing calcium.

15.Oral care ingredients (oral care products)

Application areas：Oral care products.

Related Products: fTCP remineralizing toothpaste, TCP containing anti-cavity toothpaste, children anti-cavity toothpaste, fluoride synergistic toothpaste, enamel repair toothpaste, mouthwash, chewing gum, etc.

Why it works for this purpose: Tricalcium phosphate slowly releases calcium and phosphate ions in the mouth, providing remineralization materials for the tooth enamel, promoting early cavity repair, and synergistically enhancing the anti-cavity effect of fluoride.

Summarize：Tricalcium phosphate (TCP, Ca3(PO4)2, CAS 7758-87-4) is a multi-purpose agent used in a wide range of industrial and consumer applications. It has many application in ceramic glazes and body fluxes, raw materials for bone china, fluxing and clarifying agents for glass and enamel, phosphate fertilizer and soil conditioner, calcium and phosphorus supplements for feed, filler for plastic and rubber, rust-preventive pigment and filler for coating, polishing and grinding material, defluoridator for drinking water, binder of refractory material, anti-caking agent of salt and powder food, calcium fortifier, baking food processing aid, stabilizer and processing aid of dairy products, ingredients for oral care and health products through high-temperature fluxing, calcium and phosphorus nutrient supply, anti-caking of fine powder, passivation and rust-preventive, enamel, remineralization, fluoride adsorption, inert filler. Major uses are ceramic glazes, bone china, phosphate fertilizers, food anti-caking and calcium fortification.