A hard thing to behold
As heavy as gold and (in its processed form) as hard as a diamond; it has the highest melting and boiling points of all the chemical elements. We are of course talking about tungsten. Continue reading
Tungsten, also known as wolfram, was discovered by chance, during tin extraction, at the end of the eighteenth century. The “wolf” part of tungsten’s lesser-known name stems from this mineral’s lupine-like tendency to “eat up” tin ore. The “ram” element comes from a German word that can mean “soot”, “froth” or “slag”, from its greyish-black appearance. Tungsten, and especially tungsten carbide (a combination of tungsten and carbon), are nowadays high-performance materials that each of us is likely to have held in his or her hand at some time.
A strong wind blows
Shock tubes supplied by Kuhn Special Steel are used in the extraction of tungsten carbide. The first step is to extract pure tungsten. This reduction process is carried out by heating, along with hydrogen, in shock-tube furnaces at temperatures of up to 1,180°C. The furnace is fitted with up to twenty of these shock tubes, which form a closed circuit in which the materials are separated. The shock tubes, which need to be extremely resistant to heat and wear, are made of stainless steel supplied by Kuhn. Further chemical treatment during the reduction process results in powdered tungsten of approximately 98% purity.
Writing with tungsten carbide
As pure tungsten is very brittle, it is combined with carbon at a very high temperature. This takes place in a hydrogen atmosphere. The result is tungsten carbide, a material with a degree of hardness comparable to that of diamonds. It is for this reason that products made of tungsten carbide can be found in industrial tools, such as drills and milling machines, that are particularly subject to stress. But that is not all: virtually every ballpoint pen contains a spherical tip made of tungsten; hence the high probability of having held tungsten in your hand. You might say that Kuhn Special Steel is there throughout the cycle, as we supply the shock tubes used in manufacture and also sign contracts with ballpoint pens that require shock tubes for their production.