Phosphorus

Phosphorus is a non-metallic element used to manufacture fertilisers and in various industrial products, including batteries.

Phosphorus (P)

Phosphorus is a non-metal element, which is the 12th most abundant element in the Earth’s crust. ¹ It does not naturally occur in its elemental form but instead can be found in various compounds and minerals. Phosphorous is most commonly extracted from phosphates, which are phosphorous salts containing phosphorus ions.² Phosphates are extracted from phosphate rocks and are also a by-product of the steelmaking process.³ Phosphorous, along with nitrogen and potassium, is essential for the manufacture of a broad range of fertilisers, and is also used to manufacturer batteries, and in the manufacture of incendiary ammunition and matches.

Phosphorus is predominantly derived from phosphate rock, for which China was the largest producer in 2022, extracting 85 million tonnes – or 39% of global production, followed by Morocco (18%) and the United States (10%). Morocco holds by far the largest fraction of global phosphate reserves, with an estimated 50 billion tonnes, or 70% of known reserves in 2022.⁴⁵Phosphate rock reserves are primarily composed of sedimentary phosphorites, with the largest deposits in northern Africa, the Middle East, China, and the US. Approximately 5% ⁶ of the world’s phosphate rock is found in igneous forms, the type of rock that is needed to produce the purified phosphoric acid used in battery manufacture. There are igneous phosphate rock deposits occurring in Canada, Finland, Russia, and South Africa.⁷

Generally, the greatest ESG risks in the phosphorus supply chain are a result of water pollution, which can result in negative public health and biodiversity impacts. Bodies of water in Florida have been reported as being contaminated with phosphates from phosphate rock extraction, which can accumulate over time to cause eutrophication in marine ecosystems. High phosphate concentrations in drinking water can be toxic to humans with kidney disease,⁸ although the most significant risk is to agricultural workers coming into dermal contact with organophosphates contained in insecticides.⁹

There have also been instances of smuggling of phosphorus extracted in Syria into Europe to evade economic sanctions on private Russian entities that ultimately own the rights to the Syrian phosphate mines.¹⁰

Main uses and applications

The primary commercial source of phosphorus is phosphorite, commonly referred to as phosphate rock, with significant quantities also derived from vivianite and wavellite. Phosphorus occurs as one of three allotropes i.e., different physical forms of phosphorus molecules: white, red, and black phosphorus, although their true colours do not exactly reflect this nomenclature.¹¹ White phosphorus (sometimes referred to as yellow phosphorus) is a result of industrial manufacturing, which is spontaneously flammable when exposed to air at temperatures of 35° C (95 °F) and highly toxic.¹² Red phosphorus ranges from orange to purple in colour and is created by heating the white form of phosphorus to temperatures around 200- 250 °C (390-480 °F). Black phosphorus is made under pressure, resembles graphite, and has a high electrical conductivity.¹³

Phosphorus is utilised in a wide range of applications. Concentrated phosphoric acids can be used to manufacture fertilisers, with 95% of the phosphate rock mined in the United States used to make either fertiliser or food supplements for animals. It is also an essential macronutrient for humans and can be used as an alloying agent and to produce pyrotechnic products.¹⁴ Phosphorous sulphides can be used to make matches, with phosphorus halides and oxides widely being used in the synthesis of organic compounds. Its flammable properties also lend to utilisation in military applications such as incendiary devices and smoke screens. Additional applications of phosphates also include organophosphorus detergents, insecticides, toothpaste, and oil additives.¹⁵

Almost half of all electric vehicles use lithium iron phosphate (LFP) batteries, which can also be used in large-scale energy storage facilities, making phosphorous a critical mineral for the decarbonisation of industry and the green transition.¹⁶ However, approximately only 10% of sedimentary phosphate rock feedstock is suitable to produce purified phosphoric acid, which is necessary to manufacture LFP batteries. Furthermore, of the small minority of phosphate rock that is found in igneous form, only the purest 1% occurs as igneous anorthosite that is suitable for producing large amounts of LFP battery-grade PPA.¹⁷ As the demand for energy storage in batteries increases in the coming decades, the supply of appropriate phosphate rock represents a critical choke point in the supply chain, as only a small fraction of mined phosphates is suitable for manufacturing batteries.

Steelmaking processes create large amounts of slag as a by-product, which are partially comprised of phosphates. Given that the approximate production of raw steel was 1.9 billion tonnes globally in 2022, significant quantities of phosphorus are contained in the by-products from steel manufacture.¹⁸ Although some cost-effective approaches to recovering high quality phosphate feedstocks from steelmaking slag have been demonstrated,¹⁹ the phosphorus extraction processes are not yet mature and scaleable for the purposes of LFP battery manufacture.²⁰