A homecoming, three centuries on

In the closing years of the 18th century, the D’Elhuyar brothers identified the 74th element on the Periodic Table, symbolised by the letter W for Wolfram after the implementation of a doctrine they learned in Uppsala, Sweden. Little did they imagine back then that this material would be returning to the alma mater academic studies country, to provide the heart of one of the most important science and technology facilities of the 21st century, the European Spallation Source. 

History, therefore, is repeating itself, three centuries on. Spain and Sweden have been reunited by this material, Wolfram, as it becomes the core element for this facility.         

Wolfram is a natural element found in rocks and minerals. It is a metal whose main feature is an extremely high fusion point, which means that it can withstand high temperatures while retaining sound mechanical properties (low levels of deformation).

This element has a key part to play in what will become the most powerful neutron spallation source in Europe over the next few decades. With its hardness, surpassed only by diamonds, its exceptionally high fusion point and its density, Wolfram will be the main component of the target wheel for this source. The target is the place where the proton collision takes place, and as such, can be considered as the centre of the neutron source. It is made up of a series of Wolfram blocks inside a 2.5-metre diameter wheel against which the proton beam is projected in a radial direction. Inside the wheel, there is a set of channels through which helium circulates at high speed to extract the heat generated during spallation. The wheel turns at ~0.5 Hz so that each firing of the accelerator impacts on a different area of the wheel, distributing the heat around the entire perimeter.

Spain has always enjoyed a close relationship with this material, ever since it was discovered by the D’Elhuyar brothers in the Guipuzcoan town of Bergara, and continuing through the glory years that it brought to towns in western parts of Spain during the Second World War. Wolfram had great strategic value for Nazi Germany, which used it to reinforce its rockets, and this led to a golden age for the mines located on the Iberian Peninsula that lasted for decades.

The political and financial interests surrounding this mineral, which is found in Spain but scarce around the rest of the world, continue to play a key part in the reopening of the mines which closed 20 years ago. Wolfram production will increase over the next few years as old shafts are reopened and new ones are sunk with the large-scale investments being made in Spain by major multinationals.

While Wolfram may have been strategic material for conflict during the Second World War, it is used today to manufacture electronic devices, mobile telephones, tablets, heavy machinery, medical materials, in power plants, for transport and in numerous other areas. In other words, its strategic value lies not just in its scarcity, but also in its usefulness.

This scarcity, combined with the multiplicity of applications that the material lends itself to, have meant that it has now become strategically viable to reopen the mines in the Mid-West of Spain to extract it. In the not too distant future, it may be possible for Wolfram production to begin again. Until that time, the amount needed to manufacture the target wheel for the European Spallation Source will have to be sourced from other countries which currently produce this mineral that was discovered by the D’Elhuyar brothers sometime around 1783.