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Metallic iron is virtually unknown on the Earth's surface except as iron-nickel alloys from meteorites and very rare forms of deep mantle xenoliths.Although iron is the fourth-most abundant element in the Earth's crust, composing about 5%, the vast majority is bound in silicate or, more rarely, carbonate minerals, and smelting pure iron from these minerals would require a prohibitive amount of ...
The gray spheres are oxygen, green are divalent iron, blue are trivalent iron. Also shown are an iron atom in an octahedral space (light blue) and another in a tetrahedral space (gray). Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe 2+ Fe 3+ 2 O 4.
Its name comes from the Ancient Greek word σίδηρος (sídēros), meaning "iron". A valuable iron ore, it consists of 48% iron and lacks sulfur and phosphorus. Zinc, magnesium, and manganese commonly substitute for the iron, resulting in the siderite-smithsonite, siderite-magnesite, and siderite-rhodochrosite solid solution series. [3]
Iron shows the characteristic chemical properties of the transition metals, namely the ability to form variable oxidation states differing by steps of one and a very large coordination and organometallic chemistry: indeed, it was the discovery of an iron compound, ferrocene, that revolutionalized the latter field in the 1950s. [59]
Limonite (/ ˈ l aɪ m ə ˌ n aɪ t /) is an iron ore consisting of a mixture of hydrated iron(III) oxide-hydroxides in varying composition. The generic formula is frequently written as FeO(OH)·nH 2 O, although this is not entirely accurate as the ratio of oxide to hydroxide can vary quite widely.
Iron(II) chloride tetrahydrate, FeCl 2 ·4H 2 O. In chemistry, iron(II) refers to the element iron in its +2 oxidation state. The adjective ferrous or the prefix ferro-is often used to specify such compounds, as in ferrous chloride for iron(II) chloride (FeCl 2). The adjective ferric is used instead for iron(III) salts, containing the cation Fe 3+.
The mineral pyrite (/ ˈ p aɪ r aɪ t / PY-ryte), [6] or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S 2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral .
Iron ore was also used as a flux in the smelting of copper. These agents served various functions, the simplest being a reducing agent, which prevented oxides from forming on the surface of the molten metal, while others absorbed impurities into slag , which could be scraped off molten metal.