Tungsten
Tungsten (W) is a gray-white metallic element that is stable and is very resistant to acids and bases. Tungsten has the highest melting temperature of any metal (3422 ° C or 6192 ° F), and the second highest of all elements (carbon is highest).
Type
Element (Minerals/Ores of)
Mineral Classification
Tungstate
Chemical Formula
scheelite (CaWO4, calcium tungstate) and wolframite ((Fe,Mn)WO4, iron-manganese tungstate).
Streak
White (sheelite), Redish Brown (wolframite)
Mohs Hardness
4.5-5 (sheelite), 4-4.5 (wolframite)
Crystal System
tetratongal (sheelite), monoclinic (wolframite)
Color
Colorless, white, gray, brown, pale yellow, yellow-orange, pale shades of orange, red, green; may be (sheelite)
Grayish to brownish black (wolframite)
Luster
vritreous, adamantine (sheelite), submetallic, resinous (wolframite)
Fracture
Subconchoidal, Uneven (sheelite), Uneven, Rough (wolframite)
Description
Tungsten (W) is a gray-white metallic element that is stable and is very resistant to acids and bases. Tungsten has the highest melting temperature of any metal (3422 ° C or 6192 ° F), and the second highest of all elements (carbon is highest).
Relation to Mining
Tungsten is retrieved from the ore minerals scheelite (CaWO4, calcium tungstate) and wolframite ((Fe,Mn)WO4, iron-manganese tungstate). A significant amount of tungsten is recovered through recycling of scrap tungsten products.
Uses
Tungsten is mixed with carbon to make a very strong, very resistant material called tungsten carbide. Tungsten carbide is used to make cutting tools and wear-resistant tools for metalworking, drilling for oil and gas, mining, and construction.
Because it has such a very high melting point and low vapor pressure, tungsten is used in high temperature situations. For instance, the filaments in light bulbs are made of tungsten. It is used in other applications in electronics as well.
When added to steel, tungsten increases its strength. It is alloyed (mixed with) other metals to make “superalloys” which have special physical properties of high strength and heat resistance. Some of the applications for such superalloys are in turbine engines for jet aircraft and energy generation.
It is also used in textile dyes, enamels, paints, and for coloring glass.
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