December 2011 Updates To The TMR Advanced Rare-Earth Projects Index

@Paul Gubbens: thanks for your comments. I would agree that terbium (Tb) additions are more effective than dysprosium (Dy) for improving the coercivity (resistance to demagnetization) of neodymium-based magnets. Not only is Tb less available than Dy (and significantly so), it has historically been much more expensive than Dy, and of course unlike Dy, Tb has significant demand in the production of phosphor materials.

@Toly: while holmium (Ho) does have a high magnetic moment, it’s only a fraction higher than that of dysprosium (Dy) or even erbium (Er). The existence of a high magnetic moment alone does not lead to the formation of good permanent magnet materials. In fact, just like Dy and other heavy rare earths, when alloyed, the magnetism of Ho atoms acts to partially cancel out the useful magnetism of transition metals such as iron (Fe) or cobalt (Co).

This is the reason why when Dy is added to neodymium-based magnets, the strength of the magnet actually goes DOWN with increased Dy. We add the Dy to improve the ability of the magnet to resist being demagnetized (known as the coercivity). Increased temperature is a common source of such demagnetizing effects. Incidentally, this increased resistance is NOT as a result of increasing the Curie temperature of the magnet – a common misunderstanding of the role of Dy in these magnets (if you really want to know, increased coercivity comes from increasing the anisotropy field for the magnet, which makes it harder for the N-S orientation of the magnet to get “flipped”).

So no – you won’t see Ho-based permanent magnets, just like you won’t see Dy- or Tb-based permanent magnets, because they simply wouldn’t work. It’s a shame that in their misguided efforts to demonstrate that every rare-earth element is useful, a lot of folks in our sector (and I’m not referring to you, Toly!) love to simply regurgitate excerpts from Wikipedia willy nilly, without understanding any of this… the fact of the matter is that some rare earths are more useful, in practical, everyday terms, than others.

@Rahul Jalan: I don’t agree that the news about Baotou will necessarily lead to a “huge spike in prices” of light rare earths, or a “severe supply shortage”. It all depends on how much capacity is available elsewhere in the rare-earths industry in China (some estimates are that the total including Baotou is 200-250 ktpa – much higher than is needed, even excluding Baotou), and whether or not this is simply an issue of paperwork not being filed on time. Furthermore, I expect that there will be a reduction in export quotas anyway in 2012, simply because consumers outside of China are not using them.

I disagree that the issue of environmental standards is not a genuine factor in the decisions being made about the industry in China. While I don’t buy the connection between those standards, and export licenses (they should of course be applied across all producers, and for all production), there are many indications that China is serious about implementing stricter pollution standards.

As for the inclusion of Nd-Fe-B magnet alloys in next year’s export (not mining) quotas – I’ve heard folks talking about this too, but I’d be very surprised if that happened.

@ Carlos Braga: as stated above in the article, I am in the process of verifying the associated data for the Araxa project, as well as others, and will report on them in the near future.

@ Gary Sutton: you can already get grades of Nd-Fe-B magnets with higher Br (magnet strength) and lower coercivity. As you alluded to, you can also get significant Br values from older materials such as the Alnico family. Usage of specific materials depends on the design of the device into which you are placing the magnets, and whether or not there are potential stray magnetic fields from adjacent magnets or other devices, if there will be heating etc. As a rough rule of thumb, the longer and skinnier a magnet is (with the N-S orientation parallel to the long axis of the magnet), the better the magnet will resist demagnetization, but that might not be a convenient shape for a given application. In motor designs, for example, the shape is quite the opposite – the magnetic orientation is typically through the thinnest dimension. It’s definitely a case-by-case situation, determined by the magnetic circuit designer.

@iamwhatiam: I had the opportunity to visit Alkane’s pilot plant earlier this year – check out http://www.barnswood.com/tmr/wp/?p=3757 for the details.

@iamwhatiam: I don’t give stock tips or investment advice, I’m afraid. What I will say is that I think that Alkane’s Dubbo Zirconia Project has an excellent chance of going into production.