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Material World
Element · P

Phosphorus

An element with no substitute in agriculture, mined from a small number of deposits, and discovered by boiling urine.

Agricultural input

Phosphorus was isolated in 1669 by an alchemist evaporating urine in search of gold. It glows faintly in air — the property that named it — and its white allotrope ignites spontaneously.

Its modern importance is agricultural and absolute. Phosphorus is essential to every living cell and has no chemical substitute whatsoever: unlike energy sources, which can be swapped, a crop deprived of phosphorus cannot be given something else instead. Nearly all of it comes from phosphate rock, and the economically viable deposits are geographically concentrated.

Uses

Phosphorus is fertiliser first and everything else second. There is no substitute for phosphate in agriculture — a plant that cannot get phosphorus does not grow, and no chemistry can be invented to replace it.

Beyond that: phosphates in detergents and food processing, phosphoric acid in soft drinks and rust treatment, and the red allotrope on the striking strip of a matchbox. Organophosphorus chemistry gives both pesticides and nerve agents, which are closer relatives than is comfortable.

Medium confidence Weak evidence

How we know: checked recently · only one source, so there is nothing to cross-check it against · stated directly by the source.

How this connects

Where a connection has been confirmed by an outside reference, that reference is named beside it.

is used as

  • Fertiliser — application · the P in N-P-K, and the one with no chemical substitute

is extracted from

  • Apatite — mineral · essentially all phosphorus, and phosphorus has no substitute in agriculture

is produced by

  • Smelting — process · white phosphorus, reduced from phosphate rock with coke and silica in an electric furnace and condensed under water

is found in

  • Weathering steel — alloy · 0.06–0.15% · a deliberate addition here, where in most steels it is an impurity to be minimised
  • Ivory — material · in the apatite — it is a phosphate mineral, not a carbonate one
  • Bone — material · in the apatite
  • Lithium iron phosphate — compound · in the phosphate group, which holds the oxygen covalently and is the whole of the safety argument
  • Apatite — mineral
  • Monazite — mineral
  • Xenotime — mineral Wikidata

Sources

  • Material World
    Our own writing
  • Wikidata
    Wikimedia Foundation · Creative Commons CC0 1.0 Universal (public domain dedication)
  • PubChem
    US National Library of Medicine · Mixed — aggregated third-party content, rights retained by depositors
  • NIST — National Institute of Standards and Technology
    United States Department of Commerce · US Government work — public information, credit requested

Questions this page answers

Where it comes from, and what it becomes

Follow Phosphorus back to what it starts as, and forward into what it becomes. Each step is a documented one — a real route material takes, not a chain of inference.

Upstream — what it comes from

  • Phosphorus → is produced by (white phosphorus, reduced from phosphate rock with coke and silica in an electric furnace and condensed under water) → Smelting → takes as input (as the element removed, not added) → Oxygen → is produced by (the largest output by tonnage, and the reason air separation units sit beside steelworks) → Air separation → takes as input (the feedstock, and an unusual one in being free, unlimited and available anywhere — the cost is entirely the energy to liquefy it) → Air
  • Phosphorus → is extracted from (essentially all phosphorus, and phosphorus has no substitute in agriculture) → Apatite
  • Phosphorus → is produced by (white phosphorus, reduced from phosphate rock with coke and silica in an electric furnace and condensed under water) → Smelting → takes as input (roasted to drive off sulfur, then reduced to copper) → Chalcopyrite
  • Phosphorus → is produced by (white phosphorus, reduced from phosphate rock with coke and silica in an electric furnace and condensed under water) → Smelting → takes as input (reduced with carbon to metallic tin) → Cassiterite
  • Phosphorus → is produced by (white phosphorus, reduced from phosphate rock with coke and silica in an electric furnace and condensed under water) → Smelting → takes as input (reduced with coke in a blast furnace) → Hematite
  • Phosphorus → is produced by (white phosphorus, reduced from phosphate rock with coke and silica in an electric furnace and condensed under water) → Smelting → takes as input (the phosphate rock charged to the electric furnace, with coke to reduce it and silica to take up the calcium) → Apatite

These are the most distinct paths back. Phosphorus can be traced through others besides.

Downstream — what it becomes