Stan: I don't recall, Senator :-) Fran: to my knowledge, the Pitinga tin mine tailings study is of interest because of potential access to interesting quantities of heavy rare earths. The presence of heavies would give such a process a higher probability of commercial success than a more general process, focused on the presence of rare earths with likely higher proportions of light rare earths.

Hello Minedigger: thank you for your comment and feedback. I believe that there is scientific value to the work being done at Leeds [not Liverpool] on rare earth extraction from titanium dioxide; however, just like similar proposals to, for example, extract rare metals from sea water, there is little indication that such processes can ever be viable from a commercial point of view. There are other, relatively more cost-effective ways to achieve the same aims. The recent publicity surrounding the work at Leeds was not, in my humble opinion, commensurate with the likely commercial value of the project. Of course, I would love to be proven wrong on this, and I will of course continue to follow the work at Leeds and elsewhere with interest.

Tracy: the article has now been posted. Stan: Great question! I had assumed that, since Arnold was acquiring their equipment, coupled with the USMMA's regular reference to Electron Energy as the only remaining Sm-Co producer in the USA, that Semicon was no longer producing. Perhaps that isn't the case - can you shed more light on this for us? Thanks!

Alpius: my understanding is that the acquisition target is likely to be the Santoku facility in Arizona, which used to produce Sm-Co magnet materials. While Arnold and Molycorp were [and possibly still are] in discussions, Arnold is a user of rare earth metals and alloys, not a producer, and uses such materials at facilities outside of the USA where it produces rare earth-based permanent magnets. That said, Arnold just last month announced that they had acquired the equipment and other assets of Semicon Associates, a former Sm-Co magnet manufacturing facility.

Prescient11: are you referring to Chinese supply to itself, or to the rest of the world, or both?

Jesse: the other rare earth elements are not used in permanent magnets, but do have a variety of other uses. As you pointed out, a number of rare earth exploration and mining company Web sites do list what some of those uses are.

The principal REEs used in magnet alloys are: 1) samarium, for 1-5 and 2-17 type rare earth magnets, with some additions of praseodymium and gadolinium depending on the grade; 2) neodymium, for 2-14-1 type rare earth magnets, with some additions of praseodymium, dysprosium and terbium depending on the grade.

Loquacite: what if the pundits are right? What if there is far LESS future demand than the happy clappy "there'll be a plugin hybrid in every garage by 2020" crowd would have us believe? The Miami Herald article simply reports on a recently-stated goal from a Japanese government ministry. While the Japanese government is generally more savvy with regard to materials supply chain issues than many others, this would not be the first time such an entity has made a bold statement without having any real clue of what is involved in terms of the required processes from the mine face to end product. Saying, for example, as the Miami Herald report does, that "prices of lithium ion batteries used in next-generation vehicles SHOULD be reduced to one-seventh of 2006 prices by 2015" is not exactly the same as DOING what is required to make that happen. Setting ambitious goals to inspire the denizens of the market place to extend their reach and to achieve worthy objectives is one thing. Doing so while ignoring the economic and engineering realities of the present day and recent history is quite another. Give me pundits unwilling to drink the Kool-Aid over those sipping the sweet stuff just to sell more subscriptions, any day...

Prescient11: I would agree that indications are that this time around, things may well be different because of Chinese industry being constrained by their own HREE supplies. On your other point: RareMetalBlog endeavors to cover the important news in this space; we're always looking for ways to improve what we do, and so I thank you for your suggestions for future coverage.

Prescient11: as my previous commentary here and elsewhere should indicate, I would love nothing more than to see a revival of fundamental and applied R & D of rare earths in North America. I was a rare earth alloy chemistry research scientist at the beginning of my career, and so I "get it". However, I am somewhat pessimistic about any large scale revival of R & D in the near term, if the industry is left to its own devices. Molycorp's CEO Mark Smith often tells the story of his company having to "grow their own" scientists as they embarked on trying to improve and optimize their processes at Mountain Pass. That's a tough challenge to overcome - but hey - I'm game if you are. Folks of all levels of expertise in this space are free to discuss the size of the ore bodies at Strange Lake, Misery Lake or any other lake; but without the use of objective, independently-verified data to inform that discussion, personally I see little value in it. Of course, as someone whose interest comes from the strategic / technology perspective, I readily acknowledge that this viewpoint might not be shared by investors looking to make a quick buck or ten by buying on the rumor...

Prescient11: I wish Molycorp well with its XSORBX cerium-based product, but I'm not going to start worrying about cerium supplies on the basis of forward-looking statements in a company's literature, unless they can be supported with additional objective evidence. Regarding Quest's TREO numbers: respectfully, there's quite a difference between numbers on the back of an analyst's envelope, and those drawn from a 43-101 compliant report. On what specific basis was the 3-400 million tonnes number derived?

Prescient11, please my response to your other comments on Quest, here : http://treo.typepad.com/raremetalblog/2010/04/blog-raremetalblog-week-in-review-041210-041810.html

I've read the Molycorp document [available to anyone that cares to read it via http://www.sec.gov/Archives/edgar/data/1489137/000095012310035593/d70469sv1.htm ]; there's some interesting stuff in there, but nothing that I would describe as a "blockbuster revelation". As for Quest Rare Minerals [formerly Quest Uranium], from where are you getting your data, Prescient11? Quest's Web site and its April 7, 2010 news release, which gives details of its 43-101 report for the B-Zone at Strange Lake, Quebec, describes an Inferred Resources of 114.8 million tonnes grading at 1.00% TREO, with a 0.85% cutoff. This equates to 1.14 million tonnes of TREO in the ground. At a more likely 1.0% cutoff grade, Quest's data shows a resource size of 40.3 million tonnes, grading at 1.16% TREO, which would equate to 644,800 tonnes of TREO...