In 1783, the two Spanish chemist de Ehujar brothers isolated tungsten in its purest variety. Tungsten is a greyish-white, lustrous metal. It is reliable at room temperature, then again, at temperatures 1650C or above it shows highest tensile strength. It has tremendous corrosion resistance and most importantly used for making alloys. Alloys made by Mixing Tungsten with Magnesium and Calcium glows and produces phosphorescent this is used for making mild bulbs. Most of these unusual properties are as a results of the 1/2-crammed 5d electron shell. Based on these properties, tungsten and its alloys have many very important applications.
Tungsten is discovered in several ore forms. Its two main commercially mined ores are wolframite and scheelite. Wolframite is the most abundant resource of tungsten, as it accounts 70% of the complete tungsten world.
Wolframite: It is the chief ore of the metal tungsten. Wolframite is a reddish-brown to grayish-black lustrous mineral. It is a strong and quite dense material. Wolframite peculiarly occurs in quartz veins and pegmatites rock. Separation system consists of gravity separation (spirals, cones, tables), in combination with magnetic separation. Due to its excessive melting temperature, it is an ideal material for electric filaments machining tungsten gear moreover armor-piercing ammunition. Notable occurrences: Nanling Range, China; Colorado, USA; Russia; Bolivia; Korea; England; Portugal; Myanmar and Australia.
Scheelite: It is a calcium tungstate mineral. Scheelite is a subordinate ore of tungsten. Czochralski process is used for the synthesis of Scheelite. At times it is used to imitate diamond, as a scintillator. Its ore have a color that range from golden yellow, brownish inexperienced to dark brown. Its gravity is excessive and its hardness is low.
Notable occurrences: Hollinger Mine, Ontario, Canada; Saxony, Germany; Australia; California, Arizona, Utah and Colorado, in the USA; South Korea; England; and China.
Extraction Method of tungsten:
The common extraction approaches are surface mining and underground mining. The replacement of approaches depends upon several elements such as physical and chemical properties of the mineral, tonnage, occurrence, geometry and the depth of the ore frame.
Surface mining: It is additionally is called Open-pit mining. This system is utilized if close to-surface ore frame is massive. The whole ore frame is mined during the extraction operation. Hydraulic mining is usually used in the reclamation of tungsten.
Underground mining: Underground mining is preferred as surface mining is an opulent process. Underground process tungsten ore is mined in stops. It contains a kind of horizontal levels at dissimilar depths below the outside.
Tungsten Uses & Applications
Tungsten has huge industrial software peculiarly as a results of its rare properties.
It is beneficial for glass-to-metal seals as a results of its exceptional thermal expansion properties.
It is used in electrical contact points for car distributors.
Winding and heating elements of electrical furnaces are made of Tungsten.
Tungsten and its alloys are used widely for filaments for electric lamps, television tubes.
It serves a large range of software in the metal evaporation work.
Fluorescent lighting use calcium and magnesium Tungstate.
Machining Tungsten carbide is basic for mining, metal working and petroleum Industries.
Tungsten disulphide is used as excessive-temperature lubricant.
The chemical and tanning industries use tungsten salts.
Tungsten bronzes and other tungsten compounds are used in paints
It has missile and excessive-temperature applications.
Devices with excessive speed software contain alloys of Tungsten.