Tungsten is one of the toughest metals on earth, with a high density, high melting point, high tensile strength and a low vapor pressure. This makes it useful for many industrial processes. Tungsten carbide is one of the strongest materials known and is widely used in machine cutting tools. However, the amount of tungsten available worldwide is limited and finite. This is why tungsten recycling is just as important as tungsten processing from the point of view of the industries that rely on the material.
The heavy stone that lives up to its name
Tungsten is a silver colored metal, discovered in 1781. The name means ‘heavy stone’ in Swedish and the element certainly lives up to its name. It is one of the toughest metals known, being twice as dense as steel, with the highest melting point of any known metal. It melts at 3422 degrees Centigrade which is over 6000 degrees Fahrenheit. Combined with carbon to form tungsten carbide, it forms one of the strongest alloys used for industrial and manufacturing purposes.
Tungsten carbide, which is often just called carbide, is used in making the strongest heavy-duty metal-cutting tools and wear parts. It is valued for being able to achieve the highest speeds as well as prolonging tool life. Tungsten was first used in tool cutting in 1925 by Dr. Samuel Hoyt, a scientist at the Lamp Department at General Electric. In 1933, Philip McKenna added titanium to increase cutting speeds even further.
Uses for tungsten alloys
Cutting tools nowadays use cemented tungsten carbide, in which grains of tungsten carbide are cemented with other materials in a cobalt binder. Tungsten also has a high tensile strength and high vapor pressure, making tungsten alloy products useful in all kinds of manufacturing processes. Besides cutting tools, wear parts and spray powders, tungsten is used in high-temperature applications like fluorescent lighting filaments, heating elements, etc. Tungsten processing begins with ores that appear only in combination with calcium, iron or manganese.
Despite its usefulness and versatility, tungsten processing and manufacturing are limited by the amount of the metal available in the natural state. It makes up only 1.25 grams out of every 1,000 kilograms of the Earth’s crust. About 80% of the tungsten used nowadays is mined in China. Due to limited supplies and high prices, they has been an increase in the recycling of tungsten and its alloys like tungsten carbide.
The importance of tungsten recycling
Besides its use in various manufacturing processes, tungsten is also classified as a strategic material. However, the amount of tungsten available worldwide is finite, which makes the recycling of tungsten and tungsten products both necessary and profitable. Tunsgten scrap fetches a high price, though this can vary with its grade, form and quality.
Most tungsten recyclers will import tungsten scrap from locations worldwide. They will also travel to worldwide to assess and validate sample materials. Tungsten scrap is most often found contaminated with copper, chrome and silver braze. Their presence will affect the price of the scrap metal.
Tungsten is one of the hardest and strongest metals, and tungsten alloys are widely used in industrial processes and parts. They are also used in high temperature applications because the metal has the highest melting point of any known metals. Because of the limited amounts of tungsten available worldwide, recycling tungsten scrap is as important as tungsten processing.