June 13, 2011
Tungsten is a gray-white metallic element that is stable and is very resistant to acids and bases. It does, however, oxidize in air, especially at higher temperatures Tungsten was discovered by Juan José and Fausto Elhuyar, Spanish chemists and brothers, in 1783 in samples of the mineral wolframite ((Fe, Mn)WO4). Tungsten was named from the Swedish words "tung sten" meaning "heavy stone." Tungsten's chemical symbol comes from its eariler, Germanic name, Wolfram. The name Wolfram comes from the mineral wolframite, in which it was discovered. Wolframite means "the devourer of tin" since the mineral interferes with the smelting of tin. That’s why tungsten’s symbol is a W. Tungsten is retrieved from the ore minerals scheelite (CaWO4) and wolframite ((Fe,Mn)WO4). Of the world’s tungsten reserves, nearly half are found in China. Canada and Russia also have large reserves. A significant amount of tungsten is recovered through recycling of scrap tungsten products. [1.] Tungsten is classified as a "Transition Metal" which is located in Groups 3 - 12 of the Periodic Table. An element classified as transition metals are ductile, malleable, and able to conduct electricity and heat. 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. These applications account for more than 60% of the tungsten consumed in the US each year. Because tungsten has such a very high melting point and low vapor pressure, tungsten is used in high temperature situations. It does, however, oxidize in air, especially at higher temperatures. It has the highest melting temperature of any metal (3422 degrees C, 6192 degrees F), and the second highest of all elements (Carbon is highest). For instance, the filaments in light bulbs are made of...