Phosphate rock: Extraction

Ancient sea floors mined in giant open pits

Most phosphate rock is sedimentary phosphorite laid down on ancient sea floors, with the largest deposits in North Africa, the Middle East, China and the US. Igneous apatite deposits occur in Brazil, Canada, Finland, Russia and South Africa (USGS). It is mined in large open pits, then washed and floated to raise its P2O5 grade. Nearly all marketable rock is digested with sulfuric acid to make phosphoric acid. That acid is reacted with ammonia into granular DAP and MAP fertiliser, so the chain links phosphate to sulfur and nitrogen. Gypsum is the bulky waste.

Phosphate rock is dug from shallow sedimentary beds or igneous deposits in open pits and upgraded by washing and flotation. A small amount is ground and applied directly, but most is turned into phosphoric acid by the wet process: digestion in sulphuric acid, which leaves about five tonnes of phosphogypsum per tonne of P2O5 (indicative). The acid is reacted with ammonia to make DAP and MAP, the main traded fertilisers, or purified for feed and industry. A thermal route in electric furnaces makes elemental phosphorus for chemicals. Integration matters: producers with rock, sulphur and ammonia on one site, such as OCP and Ma'aden, have the lowest costs.

Methods compared

How each method works

Overburden is removed by draglines or trucks and shovels and the phosphate matrix mined. It is slurried, screened and floated to remove sand and clay, then dried. Morocco's Khouribga and Florida's Bone Valley are classic examples. Some ores are calcined to remove carbonate and organic matter.

Large, low-cost deposits; falling grades in Florida and large land disturbance.

Hard-rock apatite ores in carbonatite or alkaline complexes are drilled, blasted, crushed and floated to a high-grade, low-impurity concentrate. Russia's Kola peninsula (PhosAgro), Finland's Siilinjärvi, Brazil and South Africa use this route.

Clean, low-cadmium rock valued in Europe; harder ore and higher milling cost.

Rock is digested with sulphuric acid (made from sulphur) to phosphoric acid and gypsum, filtered and concentrated to merchant-grade acid of about 52-54% P2O5 (indicative). The acid is reacted with ammonia in a granulator to make DAP (18-46-0) or MAP (11-52-0). More than 95% of US rock goes this way (USGS).

Flexible, proven route; needs sulphur and ammonia, both hit by Gulf disruption in 2026, and leaves gypsum stacks.

Rock, coke and silica are smelted in electric arc furnaces at about 1,500 C; phosphorus vapour is condensed as white phosphorus. It is energy intensive and is used only for chemical-grade products such as glyphosate intermediates.

Very pure product; high electricity use and few producers.

Who does it: global

Who does it: India

India is the world's largest phosphate rock importer (40.4% of import value in 2024) and the largest DAP importer: in FY2026 it sold 9.40 Mt of DAP, made 3.90 Mt and imported 6.22 Mt, so about two-thirds was imported (Chambal MD&A). Domestic rock (1.5 Mt in 2025, mainly RSMML) covers a small part of needs. DAP and NPK are sold at controlled prices under the nutrient-based subsidy introduced in 2010. The Kharif 2026 NBS budget for 28 P and K grades including DAP was about Rs 41,534 crore, Rs 4,317 crore more than Kharif 2025 (Cabinet, 8 April 2026).