** Unlike the listed Zirconium producers above (who generate by-product Hafnium), Westinghouse, USA, does not produce added value Hafnium by-products during Zirconium sponge production
*** India and China have some low-volume Hafnium production for domestic use but do not export
**** Out of total 64mt supply, not more than 30mt is produced via the Van Arkel process which satisfies the bulk of demand for very pure crystal bars of Hf preferred for super alloys. It is thought that Wah Chang produce 20 tonnes of crystal bars, Cezus 10mt per year.
* Nuclear includes power generation for electricity as well as for submarines and aircraft carriers
The pie charts for Hafnium show an imbalance between supply and demand which is further exacerbated by its disjointed structure – that is to say that out of the total supply of 64mt only 30mt of production is made by the Van Arkel process to make Hafnium crystal bars. Wah Chang is thought to produce about 20mt and Cezus about 10 mt via Van Arkel.
As with Zirconium, Hafnium, which is refined out of Zirconium when nuclear grade pure Zirconium sponge is required, is dependent on the nuclear industry for its route to the market. Without a nuclear industry there would be no Hafnium. Its presence within zircon sand at an average ratio of 1:50 versus Zirconium makes it extremely rare and not worth refining for its own sake.
What the supply pie chart tells us is that the recovery of Hafnium as by-product is only generated in parts of the world where Zirconium is produced. France and USA are the leaders in the West, and Russia/Ukraine in the CIS region. No Hafnium was traded East to West before 1991.
Hafnium’s historic use for control rods within nuclear plant and equipment (for repelling neutrons), is in decline and is satisfied by a supply of Electron Beam ingots which can tolerate up to 2% of Zr impurity. However, following theFukushimadisaster in 2011 further safety requirements in BWR (Boiling Water Reactors), where a hafnium skin is being mooted, may cause greater use of Hafnium in the short term.
Hafnium’s dominant application in the modern world is not for nuclear but for super alloys; both in aerospace turbine blades (rotating parts) and vanes (stators), as well as their equivalents in larger cast parts required for industrial gas turbines. It is thought that more than 35 mt of Hafnium goes into this sector one way or another via the production of complex nickel base alloys containing approximately 1.5% Hf. An example of a leading Hafnium-bearing Nickel alloy is MARM-247.
The super alloy industry (as mentioned above) prefers the purest form of Hafnium (crystal bar produced by the Van Arkel process) whose supply is limited to 30 mt. While supply and demand of Van Arkel in this field is close to balance, the specific demand for very pure hafnium with low Zr contents of 1%, 0.5% or <0.3%, all commanding various premia, keeps this sector volatile.
Other uses of Hafnium not requiring such high grade feed include such widely different applications as special steels on the one hand and Intel™ Pentium processors on the other (who proclaim their Hafnium content in advertisements). In both applications Hafnium’s use is to add heat resistance. Use of Hafnium in tips used for plasma cutting is another area that has seen growth reflecting the strength of manufacturing worldwide, especially in China. Hafnium in the form of Tetrachloride (HfCl4) is also seeing steady demand for metallocene catalysts.
In summary, it is thought that this market will for the foreseeable future be driven by its application in super alloys for gas turbines. Full aerospace order books as well as predictions that this industry’s demand could double within the next two decades will certainly put pressure on existing producers. Whether these producers will be encouraged, as a result, to grow Van Arkel production remains to be seen but, even if actioned, Hafnium’s dependence on Zirconium output for raw material would still remain a limiting factor.
It is perhaps worth noting that members of the MMTA specializing in Hafnium act as stockholders and merchants critical to the transfer of units from nuclear to non-nuclear industry.
Anthony Lipmann 08.10.12