Elemental phosphorus (P4) is the starting material for phosphorus-containing chemicals used in a wide range of industrial markets. Thermal (furnace) phosphoric acid, the principal first-order P4 derivative and its derivative phosphate (P2O5) salts are covered in detail in the CEH Industrial Phosphates report. Therefore, this report provides only summary information on P4 consumption via thermal acid. The focus of this report is on the relatively small-volume but important high-unit-value “nonacid” P4 market segments, particularly the production and use of inorganic phosphorus chemicals derived directly from P4.
China accounts for the largest share of elemental phosphorus capacity, at about 84%. China has greatly increased its capacity during the past decade, primarily with a large number of small plants, many of which are believed to be idle at present. Kazakhstan accounts for about 6%, followed by the United States and Western Europe, each with about 5%.
The most important chemicals derived directly from P4 are phosphorus trichloride (PCl3), phosphorus pentasulfide, phosphorus pentoxide and sodium hypophosphite, a relatively small-volume chemical used primarily in electroless nickel plating solutions. Phosphorus trichloride, phosphorus pentasulfide and phosphorus pentoxide are the building blocks for a large number of derivative inorganic and organic chemicals, which in turn are used in a wide variety of high-value specialized applications.
Complete world data for the elemental phosphorus industry are not available. The following pie chart shows consumption of elemental phosphorus by major region:
Red phosphorus is consumed mainly for flame retardants for plastics. Other uses include safety matches, pharmaceuticals, pesticides and bronze, as well as the production of ultrapure red phosphorus for electronic applications. Currently, Western Europe is the primary market for red phosphorus, followed by China and India.
Thermal phosphoric acid is the primary end-use market for elemental phosphorus and accounts for about 56% of world phosphorus consumption. Demand for elemental phosphorus has continued to decline sharply over the past decade because of environmental restrictions on the use of phosphates, particularly as a builder in laundry detergents, as well as competition from the less costly purified wet-process phosphoric acid in thermal acid markets. The largest market for yellow phosphorus in China is thermal phosphoric acid. Since China was lacking in wet-process phosphoric acid technology, almost all of downstream industrial products of phosphoric acid are produced from thermal acid.
In contrast to declining thermal acid demand, demand for the major phosphorus chemicals (phosphorus trichloride, phosphorus pentasulfide, phosphorus pentoxide and sodium hypophosphite) has increased over the past five years. Phosphorus trichloride is the leading inorganic phosphorus chemical produced from elemental phosphorus, with about two-thirds of PCl3 used to manufacture glyphosate-based herbicides.
Further growth is expected for the phosphorus chemicals covered in this report—principally phosphorus chlorides—over the next five years. However, demand for thermal phosphoric acid, currently the largest-volume derivative of elemental phosphorus, is expected to grow only slowly in all regions. In fact, the impact of slowing phosphoric acid demand is expected to result in an overall growth of about 1% for world elemental phosphorus, despite the positive demand growth for phosphorus chemicals. Demand growth will be most pronounced in China for the PCl3 derivatives—organophosphate herbicides (specifically glyphosate), plastics and elastomer additives, and sequestrants and surfactants.