What’s The Future Of Hafnium?
Hafnium is an obscure metal, even compared to others. Its uses are either in nuclear plants or super-alloys, and there are no primary mines. Moreover, it has no public pricing mechanism. But maybe we are getting ahead of ourselves. Hafnium is a chemical element with an atomic number 72 and assigned the symbol Hf. Its appearance can be described as metallic silver grey. It’s mainly found in zirconium metals, and is estimated to make up 5.8 ppm of the Earth’s upper crust. Hafnium reacts when exposed to air forming a protective film that prevents corrosion. It has high thermal neutron-capture cross-section.
- Its super alloys in combination with tungsten, titanium and niobium are used in electrodes and filaments
- It is used in nuclear plants and equipment to control the flow of neutrons.
- Small amounts of hafnium are used to increase corrosion resistance
- It’s used as a nuclear fuel rod armor metal due to its great chemical stability at very high temperatures.
Pegmatites in Malawi and Brazil, heavy mineral ore or sand deposits, and carbonatite intrusions are the main sources of zircon, or rather hafnium. Titanium ores, particularly rutile and ilmenite, yield the most zircon and ultimately hafnium. Up to 50% of hafnium in the world is produced as a by-product of the zircon extraction process.
While there are some who claim that hafnium reserves will only last ten years, it’s difficult to substantiate these claims especially since the USGS cannot make an estimate. It goes without saying that less informed sources cannot be trusted. Considering that hafnium occurs together with zircon, we can always trust that hafnium can always be a by-product of zircon extraction.
Applications of hafnium and how they affect demand and supply
The market for hafnium is much worse than the rare earth business for opaqueness. This can be attributed to the current demand, which is estimated to be 100tpa, as well as its strategic significance in aerospace. There is however potential for greater demand for hafnium, if more reaches the market, considering that limited supply is one of the main factors inhibiting its demand.
Zirconium, the metal from which hafnium is extracted, only goes through the production process when pure Zirconium sponge is needed. This makes its movement to the market dependent on the nuclear industry. If the nuclear industry didn’t exist in the first place, we would know nothing about hafnium. It is available within zircon at an estimated ratio of 1:50, making it very rare. This also makes hafnium unworthy of refining for its own sake.
Hafnium is mostly recovered as a by-product of zircon in parts of the world where zircon is produced. Such areas include Russia and Ukraine in the CIS region as well as US and France in the West. It’s also important to note that hafnium was never traded between the West and East before 1991.
The supply of electronic beam ingots that can tolerate Zr impurity of up to 2% is also threatening the demand for hafnium for control rods for controlling neutrons within nuclear equipment and plants. The Fukushima disaster of 2011 however led to implementation of further safety requirements in boiling water reactors where hafnium is being muted. This may lead to increased demand for hafnium, even if it’s only for the short term.
Contrary to common belief, the dominant application of hafnium is not nuclear, but super-alloys. It is used in both vanes (stators) and aerospace turbine blades (rotating parts). It’s also used larger cast parts, particularly ones that are required for industrial gas turbines. More than 35 mt of hafnium makes its way into this industry through manufacture of compound nickel base alloys with up to 1.5% hafnium. MARM-247 is a perfect example of a nickel alloy that contains hafnium.
The purest form of hafnium is preferred in the super-alloy industry, and is only produced by the Van Arkel process. It’s however unfortunate that the supply of this type of hafnium is limited to 30 mt. the demand and supply of Van Arkel is close to balance and while that’s the case, the demand for pure hafnium that contains 1%, 0.5% or less than 0.3% of zircon is what keeps this industry volatile.
Hafnium is also used for other applications like Intel Pentium processors on hand and special steel on the other. These however don’t create demand for such high grade hafnium like the super-alloy industry. Hafnium is used to improve heat resistance in both instances. Hafnium is also used in plasma cutting tips especially in China.
All in all, the market for hafnium is the near future will be mainly driven by its demand for use as a super alloy in gas turbines. Given the demand for hafnium in the super alloy industry as well as aerospace order books, it’s safe to say that its demand could double within the next one to two decades. This is bound to put pressure on producers. Whatever the case, the continued dependence of hafnium on production of zircon places a lot of limitations. But then again, time will tell.