Complete Guide to Tungsten Metal

http://top-seiko.com/wp-content/uploads/2013/05/tan04.jpg

Tungsten is a Swedish word which means heavy stone. Its chemical symbol is W, as it is also known as Wolfram, lapis ponderosus. The name Wolfram was given by a medieval German smelters. He found that tin ores had lower yield due to the presence of tungsten metal in them. It was found that tungsten was responsible for the consumption of tin similar to a Wolf and hence the name “Wolfram”.

In 1783, the two Spanish chemist de Ehujar brothers isolated tungsten in its purest form. Tungsten is a greyish-white, lustrous metal. It is solid at room temperature, however, at temperatures 1650°C or above it shows highest tensile strength. It has excellent corrosion resistance and most importantly used for making alloys. Alloys made by Mixing Tungsten with Magnesium and Calcium glows and produces phosphorescent which is used for making light bulbs. Most of these unusual properties are due to the half-filled 5d electron shell. Based on these properties, tungsten and its alloys have many important applications.

Tungsten ores

Tungsten is found 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 total tungsten world.

  1. 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 mainly occurs in quartz veins and pegmatites rock. Separation method includes gravity separation (spirals, cones, tables), in combination with magnetic separation. Due to its high melting temperature, it is an ideal material for electric filaments machining tungsten tools as well as armor-piercing ammunition. Notable occurrences: Nanling Range, China; Colorado, USA; Russia; Bolivia; Korea; England; Portugal; Myanmar and Australia.
  2. 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 green to dark brown. Its gravity is high 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 methods are surface mining and underground mining. The choice of methods depends upon several factors such as physical and chemical properties of the mineral, tonnage, occurrence, geometry and the depth of the ore body.

  1. Surface mining: It is also known as Open-pit mining. This method is utilized if near-surface ore body is massive. The whole ore body is mined during the extraction operation. Hydraulic mining is commonly used in the reclamation of tungsten.
  2. Underground mining: Underground mining is preferred as surface mining is an expensive process. Underground process tungsten ore is mined in stops. It contains a number of horizontal levels at various depths below the surface.

Tungsten Uses & Applications

Tungsten has huge industrial application mainly due to its rare properties.

  • It is useful for glass-to-metal seals due to 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 extensively for filaments for electric lamps, television tubes.
  • It serves a wide range of application in the metal evaporation work.
  • Fluorescent lighting use calcium and magnesium Tungstate.
  • Machining Tungsten carbide is essential for mining, metal working and petroleum Industries.
  • Tungsten disulphide is used as high-temperature lubricant.
  • The chemical and tanning industries use tungsten salts.
  • Tungsten bronzes and other tungsten compounds are used in paints
  • It has missile and high-temperature applications.
  • Devices with high speed application contain alloys of Tungsten.

Similar Articles

soil testing services brisbane australia

The pH (potential of Hydrogen) of soil ranges from 0 to 14, with 7 classified as neutral, less than 7 as acidic and greater than 7 as alkaline. While there are exceptions, the ideal pH value of soil for those wishing to grow plants or crops is generally considered to be between 5.5 and 7.

soil testing services brisbane australia

Mining site revegetation is a required step that must be completed by all mining companies. The absence of topsoil combined with the use of surplus materials in place typically makes this a challenging process. In many cases, what previously was able to sustain a flourishing ecosystem is now incapable of growing any plant life at all.

Reverse Osmosis System

Have you ever asked what’s in your drinking water? I bet you have, many times. Environmental protection agencies anywhere in the world have most recently released bulletins urging people to be aware of the fact that no matter where you are, there is always the likelihood that some toxic substance is in your groundwater.

soil testing brisbane

When the properties of soil beneath an existing structure change, it has an adverse effect on the entire structure. Such soil changes are typically attributed to environmental factors, such as extended periods of dry or wet weather.

soil testing brisbane

Prior to the commencement of construction, a site is required by law to undergo an extensive soil test to identify if it has the strength to bear the intended weight of the structure. This is conducted by an external firm and the findings are put into an official record.

How Digital Technology Has Changed Modern Hearing Aids

Modern hearing aids have come a long way from the days of basic analog hearing aids which were bulky, uncomfortable and had a lot of background noise. Thanks to advancements in digital technology over the years, digital hearings aids now offer discretion with its small, barely visible form along with a number of powerful features that really give users a life-changing experience

materials testing services companies

There are many individual elements that comprise the greater spectrum of so-called ‘aggregate’ materials, all of which play a vital role in contemporary construction. Commonly used elements include gravel, sand, and slag, among others.

mobile work aluminium platforms

Within the industrial sector, items can be forged from a number of different materials. Each company will have a good explanation for favouring one material over the other, just as each client will have their own reason for having a material preference, as well.

mobile work access platforms

Safety is, or at least should be the highest priority for any industrial facility, but more especially if it’s a chemical manufacturing plant. The hazardous materials that are managed by staff on a daily basis, combined with the company’s eagerness to meet ambitious performance goals, can have disastrous ramifications for the safety of workers if proper safety measures aren’t in place and adhered to.