Chemical fertilizer industry

　　Phosphates are commonly used in detergents as water softeners, but are regulated in some areas because algae boom-bust cycles can affect phosphate emissions in the watershed.

　　In agriculture, phosphate is one of the three main nutrients for plants and is the main component of fertilizers. Phosphate fines are mined from the phosphorus layers of sedimentary rocks. Previously it was mined and used without processing, but now unprocessed phosphate is only used in organic farming. Generally, it is chemically processed into lime superphosphate, double superphosphate or ammonium dihydrogen phosphate, which are higher in concentration than phosphate and more soluble in water, so plants can absorb them faster.

　　Fertilizer grades generally have three numbers: the first refers to the amount of nitrogen, the second refers to the amount of phosphate, and the third refers to alkaline water. So a 10-10-10 fertilizer would have 10% of each ingredient and the rest would be fillers.

　　Phosphate runoff from overfertilized farmland can be a cause of eutrophication, red tides and subsequent hypoxia. This can cause hypoxia in fish and other aquatic organisms like phosphate cleaners.

　　Refractory

　　Phosphates are used as binders in refractory materials. Phosphate binder is a refractory binder with acidic orthophosphate or condensed phosphate as the main compound and has gel properties. The binding form of the phosphate binding agent is chemical reaction binding or polymerization binding. Most of the binders prepared by reacting phosphoric acid with alkali metal or alkaline earth metal oxides and their hydroxides are gas-hardening binders, that is, coagulation and hardening can occur at room temperature without heating. Most of the binders prepared by the reaction of phosphoric acid with amphoteric oxides and hydroxides or acidic oxides are thermosetting binders, that is, they must be heated to a certain temperature to react before they can produce coagulation and hardening. Phosphate used as a bonding agent for refractories has strong bonding strength in the medium and low temperature range before ceramic bonding, so it is widely used as a bonding agent for amorphous refractories and unburned refractories.

　　Phosphorus is an important mineral element necessary for the human body. The main source of phosphorus intake by the human body is natural food or food phosphate additives. Phosphate is one of the natural components of almost all foods. Because phosphate can improve or impart a series of excellent properties to food, it has been used in food processing as early as more than 100 years ago, and a large number of them have been used since the 1970s. Phosphate is one of the most widely used and widely used food additives. As an important food ingredient and functional additive, it is widely used in meat products, poultry products, seafood, fruits, vegetables, dairy products, bakery products, beverages, In the processing of potato products, seasonings, convenience foods, etc. Phosphates used in food processing are usually sodium salts, calcium salts, potassium salts, and iron and zinc salts as nutritional fortifiers. There are more than 30 kinds of commonly used food-grade phosphates. Sodium phosphate is a Chinese food. The main consumption type of phosphate, with the development of food processing technology, the consumption of potassium phosphate is also increasing year by year.

　　In order to give full play to various phosphates and the synergistic effect between phosphates and other additives to meet the development needs of food processing technology, various compound phosphates are often used as food ingredients and functional additives in practical applications. The research and development of complex phosphate has increasingly become the development direction of the development and application of phosphate food additives.

　　food industry

　　According to the US Food Chemical Pharmacopoeia (FCC), the functions of phosphates in the food industry can be divided into 15 categories:

　　1. Sour agent: phosphoric acid

　　2. Anti-caking agent: calcium phosphate

　　3. Antioxidant: calcium hypophosphite

　　4. Buffer: diammonium hydrogen phosphate, ammonium dihydrogen phosphate, calcium hydrogen phosphate, calcium phosphate, calcium pyrophosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium acid pyrophosphate, sodium dihydrogen phosphate, dihydrogen phosphate Sodium, Sodium Phosphate, Sodium Pyrophosphate

　　5. Dough improver: diammonium hydrogen phosphate, ammonium dihydrogen phosphate, calcium dihydrogen phosphate, calcium hydrogen phosphate

　　6. Emulsifier: potassium phosphate, potassium polymetaphosphate, potassium pyrophosphate, sodium aluminum phosphate (alkaline), sodium metaphosphate (insoluble), sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium polyphosphate (vitreous), Sodium pyrophosphate

　　7. Hardener: calcium dihydrogen phosphate

　　8. Moisturizer: potassium polymetaphosphate

　　9. Starter: diammonium hydrogen phosphate, ammonium dihydrogen phosphate, sodium acid pyrophosphate, sodium aluminum phosphate (acidic)

　　10. Nutrients: calcium dihydrogen phosphate, calcium hydrogen phosphate, calcium phosphate, calcium pyrophosphate, iron phosphate, iron pyrophosphate, magnesium hydrogen phosphate, magnesium phosphate, manganese hypophosphite, sodium iron pyrophosphate, sodium dihydrogen phosphate, phosphoric acid Disodium hydrogen, sodium phosphate, sodium pyrophosphate

　　11. Preservative: sodium hypophosphite

　　12. Chelating agents: calcium dihydrogen phosphate, phosphoric acid, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium acid pyrophosphate, sodium metaphosphate (insoluble), sodium polyphosphate (glassy)

　　13. Improved starch additives: trimeta-pyrophosphoric acid, potassium dihydrogen phosphate

　　14. Tissue modifiers: potassium pyrophosphate, potassium tripolyphosphate, sodium metaphosphate (insoluble), disodium hydrogen phosphate (vitreous), sodium tripolyphosphate

　　15. Fermented food: ammonium dihydrogen phosphate, diammonium hydrogen phosphate, calcium dihydrogen phosphate, calcium dihydrogen phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate.

　　It can be seen from the above that there are two main functions of phosphate in food processing, one is a quality improver, and the other is a nutritional fortifier.