Phosphate (chemical)
Phosphate is a chemical compound widely recognized for its essential role in agriculture and various industrial processes. It primarily comes from phosphate rock, which is mined extensively in regions such as Florida and North Carolina in the U.S., as well as in significant quantities in countries like China, Morocco, and Russia. The main mineral source of phosphorus in phosphate rock is apatite, a hydrated calcium phosphate that serves as a key ingredient in the production of fertilizers. More than 95% of phosphate rock is utilized to create phosphoric acids, which are essential for manufacturing ammonium phosphate fertilizers and animal feed supplements.
Phosphate deposits are predominantly found in marine sedimentary forms, but there are also important igneous deposits. Historically, phosphate mining began in the U.S. in the late 19th century, with production linked closely to agricultural demands. The mining industry has seen significant price fluctuations, particularly during periods of increased global agricultural activity. Beyond fertilizers, phosphates have a wide range of applications in industrial processes spanning metallurgy, food preservation, ceramics, and even pyrotechnics. Understanding phosphate is vital for comprehending its impact on both global agriculture and various industrial sectors.
Phosphate (chemical)
Where Found
Phosphate is mined in Florida and North Carolina (more than 85 percent of US output), as well as Idaho and Utah. Major world producers include China, followed by the United States, Morocco and the Western Sahara, Russia, Tunisia, and Brazil.
Primary Uses
Phosphate rock is used primarily in the production of fertilizers. In the United States, more than 95 percent is used in the manufacture of phosphoric acids, which in turn are used to make ammonium phosphate fertilizers and feed supplements for animals.
Technical Definition
Phosphate rock is a general term for any earth material from which phosphorus can be extracted at a profit. The principal phosphorus-bearing in these deposits is a hydrated calcium phosphate called apatite, Ca5(PO4)3(OH). Apatite can also accommodate variable amounts of fluorine (F) and carbonate (CO3) and contains from 18.0 to 18.7 percent phosphorus.
Description, Distribution, and Forms
In its organic form, apatite is the main component of bones and teeth, and it makes up the shells of some marine invertebrates. Some phosphate deposits, particularly those in Florida, also contain certain aluminum phosphate minerals. Commercial phosphate deposits occur in two major forms: (1) marine deposits, in which phosphate-rich beds are associated with carbonate rocks (limestones, dolostones) and mudstones or shales deposited on the floor of an ocean or shallow sea, and (2) deposits, in which apatite has crystallized from formerly molten plutons (molten that solidifies below ground).
The sedimentary deposits are by far the most important phosphate producers. In the United States, these areas are located in the eastern states of Florida, Tennessee, and North Carolina, and the western states (the “western field”) of Wyoming, Montana, Idaho, Utah, and Nevada. The most widespread, continuous deposits of phosphate rock in the United States occur in the Phosphoria formation of Utah, Wyoming, Idaho, Montana, and Nevada.
By far the most important phosphate localities worldwide are in North Africa and Russia. Elsewhere in the world, significant deposits are found in North Africa, specifically Algeria, Tunisia, Morocco, and Egypt. The principal igneous deposits occur in Russia (the Kola Peninsula) and in Ontario, Canada.
History
Production started in the United States in 1867, with mining of the extensive Florida deposits beginning in 1888. Over time, the price of phosphate rock jumped—with a notable spike in 2007—as agricultural demand increased worldwide. The mining of phosphate rock has also spiked in China, as that nation’s development escalates. Interest in the production of phosphate has prompted exploration of new resources, particularly sources off the coasts of Mexico and Namibia.
Obtaining Phosphate
Phosphate rock is the ore of the phosphorus (P). It occurs mostly as marine (saltwater) sedimentary deposits in which the predominant phosphorus-bearing mineral is apatite, a hydrated calcium phosphate. Phosphate rock is mined from sedimentary marine phosphorites both on land and on continental shelves and seamounts and is available via a process in which sea organisms die and settle to the bottom of a given water body. Through mining, inorganic phosphates are obtained and can be separated from other chemicals.
Uses of Phosphate
Most of the mined phosphate rock is turned into wet-process phosphoric acid, which is used for fertilizers and supplements in animal feed. It is also used in many industrial processes, including the manufacture of phosphoric acids and other chemicals used in the fields of metallurgy, photography, and medicine and in sugar refining, soft drinks, preserved foods, ceramics, textiles, matches, and both military and commercial pyrotechnics (munitions and fireworks).