page_title: Oxygen
section_title: Industrial
hierarchical_section_title: Oxygen / Applications / Industrial
caption_attribution_description: Français&#160;: Clabecq (Belgique), coulée continue dans l'ancien haut-fourneau. English: Clabecq (Belgium), continuous casting of the old blast furnace. Nederlands: Klabbeek (België), de onafgebroken vloed van de voormalige hoogoven. Українська: Clabecq (Бельгії), випуск чавуну на одній зі старих доменних пічей. Walon: Clabek' (Bèljike), couléye sins fin di l'ancyin Òt-fornê.
context_page_description: Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. After hydrogen and helium, oxygen is the third-most abundant element in the universe by mass. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O
  ₂. Diatomic oxygen gas constitutes 20.95% of the Earth's atmosphere. Oxygen makes up almost half of the Earth's crust in the form of oxides.
  Dioxygen provides the energy released in combustion and aerobic cellular respiration, and many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and fats, as do the major constituent inorganic compounds of animal shells, teeth, and bone. Most of the mass of living organisms is oxygen as a component of water, the major constituent of lifeforms.
context_section_description: Smelting of iron ore into steel consumes 55% of commercially produced oxygen. In this process, O
  ₂ is injected through a high-pressure lance into molten iron, which removes sulfur impurities and excess carbon as the respective oxides, SO
  ₂ and CO
  ₂. The reactions are exothermic, so the temperature increases to 1,700 °C.
  Another 25% of commercially produced oxygen is used by the chemical industry. Ethylene is reacted with O
  ₂ to create ethylene oxide, which, in turn, is converted into ethylene glycol; the primary feeder material used to manufacture a host of products, including antifreeze and polyester polymers (the precursors of many plastics and fabrics). Large quantities of oxygen or air is used in oxy-cracking process and for the production of acrylic acid, diformyl-furane, benzylic acid. On the other hand, the electrochemical synthesis of hydrogen peroxide from oxygen is a promising technology to replace the currently used hydroquinone-process. Last but not least, catalytic oxidation is used in afterburners to get rid of hazardous gases.
  Most of the remaining 20% of commercially produced oxygen is used in medical applications, metal cutting and welding, as an oxidizer in rocket fuel, and in water treatment. Oxygen is used in oxyacetylene welding burning acetylene with O
  ₂ to produce a very hot flame. In this process, metal up to 60 cm (24 in) thick is first heated with a small oxy-acetylene flame and then quickly cut by a large stream of O
  ₂.
caption: Most commercially produced O
  2 is used to smelt and/or decarburize iron.
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