Phosphate rock

Phosphate rock

Phosphate rock or phosphorite is a general description applied to several kinds of rock which contain significant concentrations of phosphate minerals, which are minerals that contain the phosphate ion in their chemical structure.

Many kinds of rock contain mineral components containing phosphate or other phosphorus compounds in small amounts. However, rocks which contain phosphate in quantity and concentration which are economic to mine as ore for their phosphate content are not particularly common. The two main sources for phosphate are guano, formed from bird droppings, and rocks containing concentrations of the calcium phosphate mineral, apatite.

The United States is the world's leading producer and consumer of phosphate rock, which is used to manufacture phosphate fertilizer and industrial products.

China, the United States and Morocco are the world's largest miners of phosphate rock, each producing about a quarter of the total world production. Other countries with significant production include Brazil, Russia, Jordan and Tunisia. Historically, large amounts of phosphates were obtained from guano deposits on small islands such as Nauru, Banaba and Christmas Island, but these sources are now largely depleted.

Phosphate rock is mined, beneficiated, and either solubilized to produce wet-process phosphoric acid, or smelted to produce elemental phosphoric acid or smelted to produce elemental phosphorus. Phosphoric acid is reacted with phosphate rock to produce the fertilizer triple superphosphate or with anhydrous ammonia to produce the ammonium phosphate fertilizers. Elemental phosphorus is the base for furnace-grade phosphoric acid, phosphorus pentasulfide, phosphorus pentoxide, and phosphorus trichloride. Approximately 90% of phosphate rock production is used for fertilizer and animal feed supplements and the balance for industrial chemicals.

For general use in the fertilizer industry, phosphate rock or its concentrates preferably have levels of 30% phosphorus pentoxide (P2O5), reasonable amounts of calcium carbonate (5%), and <4% combined iron and aluminium oxides. Worldwide, the resources of high-grade ore are declining, and the beneficiation of lower grade ores by washing, flotation and calcining is becoming more widespread.

References

* [http://www.australianminesatlas.gov.au/info/aimr/phosphate.jsp Australian Mineral atlas]
* [http://minerals.usgs.gov/minerals/pubs/commodity/phosphate_rock US Geological Survey]
* [http://minerals.usgs.gov/minerals/pubs/commodity/phosphate_rock/stat USGS Statistics]
* [http://www.pir.sa.gov.au/minerals/geology/commodities/phosphate PIRSA website]


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • phosphate rock — ☆ phosphate rock n. any rock, esp. phosphorite, containing large amounts of phosphates, used as a raw material for making fertilizers, phosphorous chemicals, etc …   English World dictionary

  • phosphate rock — noun : a rock that consists of calcium phosphate largely in the form of apatite or carbonate apatite usually together with calcium carbonate and other minerals, that is useful in fertilizers and is a source of phosphorus compounds, and that… …   Useful english dictionary

  • phosphate rock — phosphorite. [1865 70] * * * ▪ Table Phosphate rock country mine production 2006 (metric tons)* % of world mine production demonstrated reserves 2006 (metric tons)* % of world demonstrated reserves China 32,000,000 22.1    13,000,000,000 26.0   … …   Universalium

  • phosphate rock — noun Date: 1870 a rock that consists largely of calcium phosphate usually together with other minerals (as calcium carbonate), is used in making fertilizers, and is a source of phosphorus compounds …   New Collegiate Dictionary

  • phosphate rock — /ˈfɒsfeɪt rɒk/ (say fosfayt rok) noun a sedimentary rock containing calcium phosphate …  

  • Rock phosphate — is a general term for rock that contains a high concentration of phosphate minerals, which commonly belong to the apatite group. Phosphate rock minerals are the only significant global resources of phosphorus. Phosphorus is an essential element… …   Wikipedia

  • Phosphate — Systematic name …   Wikipedia

  • Phosphate minerals — are those minerals that contain the tetrahedrally coordinated phosphate (PO43 ) anion along with the freely substituting arsenate (AsO43 ) and vanadate (VO43 ). Chlorine (Cl ), fluorine (F ), and hydroxide (OH ) anions also fit into the crystal… …   Wikipedia

  • Phosphate —  Ne doit pas être confondu avec Roche phosphatée. Phosphate …   Wikipédia en Français

  • phosphate — /fos fayt/, n. 1. Chem. a. (loosely) a salt or ester of phosphoric acid. b. a tertiary salt of orthophosphoric acid, as sodium phosphate. 2. Agric. a fertilizing material containing compounds of phosphorus. 3. a carbonated drink of water and… …   Universalium

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”