Comments on: Rare-Earth Terminology – A Quick Refresher On The Basics

By: Enbeng

Enbeng — Mon, 11 Feb 2013 08:08:09 +0000

Thank you for the detailed explanations. Would you also explain the column headings in the “TMC Advanced Rare-Earth Projects Index”, in particular MR(Mt), wt%, In-Situ TREO, $/t(MR), Basket Price ($/kg). In addition if you could give the words for the acronyms that would be great. TREO wt% sounds like, for every 100 units of stuff that comes out of the ground, the % that is REO so for Araxa for example, the 4.21 units would be REOs, the rest would be other elements. Basket Price sounds like it is obtained by multiplying the % of each REO in 1kg TREO, with the market price of that REO, and adding them up. So for example if 1kg of the TREO from Araxa had 50% La, 30% Ce, 20% Y and prices of each were $10, $5 and $60 respectively, the Basket Price for Araxa would be 10x.40 + 5x.30 + 60x.2 = $17.5. Is that right?

By: Jackie L. Goldsmith

Jackie L. Goldsmith — Tue, 08 Jan 2013 16:41:22 +0000

Love this group discussion…. Since I am an in field application chemist it gives me very good insight to what I am looking for……Have found in a Zinc Depost the following values……. As you can see ZINC is the main collector of all other elements including high end values for Yttrium and Gold…THese values came from GOLDSMITH ZINC PROCESS…..
as you can see these values are high because I used A Excalibur XRF
produced for the Russian Mining kIndustry in Urkanine….. Keiv, Urkanine

Zn…………….K.(Shell)…………3429.(Intensitty)…………..66.03 %(Con)
Fe…………….K…………………… 920……………………….. 17.15%
YTTRIUM…..K…………………… 445……………………….. 5.52%(1609.6oz)
Ni……………..K…………………… 352……………………….. 5.25 %
Cu…………….K……………………. 89……………………….. 1.75 %
GOLD………. L……………………. 42………………………… 1.59 %(463.60z)……..NOTICE HOW HIGHTHE GOLD IS…
Th……………. L……………………… 41………………………… 1.05 %
Zr…………….. K……………………… 91………………………… 0.98 %
V……………… K………………………. 11………………………… 0.69 %
Jackie L. Goldsmith 972 261 8187….emailjackieg1936@yahoo.com and
jackgoldsmith@att.blackberry.net….If you are interested email me back.

By: Gareth Hatch

Gareth Hatch — Mon, 17 Dec 2012 15:00:50 +0000

@Vladimir Seredin: for a moment, forget about the theoretical, atomic-scale classifications; the classification above is logical from an empirical, processing point of view. When mixed REE precipitates are being separated via solvent extraction (SX), there are different ways of doing so but a common method involves creating intermediate groupings of elements. Because of this, you will frequently see processes (the Lynas Mount Weld processing is a good example) where the result is individually separated La, Ce, Pr and Nd oxides, a mixed Sm-Eu-Gd oxide, and a third mixed oxide containing Tb-Dy-Ho-Er-Tm-Yb-Lu-Y.

These groupings are a “natural” result of the way these elements behave in the SX processes. So one could argue that the above classification is processing-based…

By: Vladimir Seredin

Vladimir Seredin — Mon, 17 Dec 2012 12:20:54 +0000

Gareth,
You misunderstood me. I like the triple REE classification, and also use it in geochemical studies of REE deposits (see the article that I sent you this year: Seredin VV, Dai S. 2012. Coal deposits as potential alternative sources for lanthanides and yttrium / / International Journal of Coal Geology. 94. 67-93). The reason is only using of threefold classification we can adequately describe the distribution of REE in rocks and ores, that actually exist in nature. However, there is the same problem as with dual classification: the vague boundaries between different groups of REE. In our case, it is quite understandable, since sharp boundaries between light, medium and heavy REE are absent in natural processes.
For example, there are three Russian triple REE geochemical classifications.
1. (La-Nd), (Sm-Ho), (Er-Lu) (Mineev, 1974);
2. (La-Nd), (Sm-Dy), (Ho-Lu) (Solodov et al., 1993);
3. (La-Sm), (Eu-Dy + Y), (Ho-Lu) (Seredin VV, Dai S. 2012).

However, I do not quite understand how I can use your classification, and whether to use it at all, if you substantiate the selection of the LREE by some of the REE physical properties, but the selection of the MREE by Chinese export quotas.

By: Gareth Hatch

Gareth Hatch — Sun, 16 Dec 2012 16:18:10 +0000

@Vladimir Seredin: thank you for your comments. I understand your perspective; I know at least a couple of other geologists and geochemists personally who also also very adamant that there should be only the LREE and HREE groups, based on the electronic structure.

The reality though is that the term MREE *IS* being used, most visibly by the Chinese, but it has always been used by the process guys. Right or wrong, my explanation above reflects that reality. I think it’s better to explain what the Chinese mean, for example, when they refer to middle rare earths in their export quota announcements, rather than to say that they shouldn’t be using the term.

Where I am sure that we will agree is on the fact that Eu and Gd should not be referred to as HREEs, since there is no justification at all for it.

By: Vladimir Seredin

Vladimir Seredin — Sun, 16 Dec 2012 15:58:58 +0000

Gareth

You well know, as high I high appreciate your work on the blog. However, I am afraid that this post is not the case.
Every REE expert well knows that any classification of REE must base on a single principle.
Meanwhile, REE may be classified according to:
1. Different physical properties (eg, the structure of the electron shells or magnetic qualities, etc.);
2. Different chemical (eg, the ability to change a valence or according to ion parameters, etc.)
3. Different technological properties (eg, the ability to leaching or separation from other REE under the influence of various reagents)
4. Different geochemical properties (eg, capacity of some rare earth abnormally enrich in REE ores of the various geological types etc.).
5. Different industrial demand in various REE (link).
6. Different prices for individual REE.

Your post gives a typical example of such classification that is base only on some of abovementioned and different REE properties. I am afraid that it may only confuse your readers. IMHO, it is unacceptable with the geological and geochemical point of view in any case.

Anup,

As I know, any fresh ultrabasic rocks don’t contain very high concentrations of REE. (BTW, what the Y content in these rocks, you are considering as very high?). However, if your rocks are fresh alkaline-mafic rocks or mafic, but hydrothermally altered rocks, the REE contents could be very high. For example, REE may be reach up to some wt% in the argillized mafic dykes of the some HREE+Y occurrences of the Russian Far East.

Vladimir Seredin

By: Christoph

Christoph — Thu, 13 Dec 2012 02:01:47 +0000

ahh …….the book seems to be very good ,…does anyone else knows where to get Rare-Earth Iron Permanent Magnets book ??

By: Gareth Hatch

Gareth Hatch — Thu, 13 Dec 2012 01:24:21 +0000

@Christoph: sorry – I only created some of the figures that appear in the book, and that was over 16-17 years ago! Even if I had a PDF copy of part or all of the book (which I do not), the Oxford University Press wouldn’t be too happy with the violation of their copyright…

Here’s a link to it at Amazon –> http://amzn.to/VXObe4. It’s not cheap – but perhaps it can be obtained through your local library…

By: Christoph

Christoph — Thu, 13 Dec 2012 01:09:59 +0000

It is not so difficult to separate RARE!! Rare-Earth Iron Permanent Magnets can we get this book or part of it? Gareth if you wrote a section can you post a pdf online for us please….

By: Gareth Hatch

Gareth Hatch — Wed, 12 Dec 2012 13:48:24 +0000

@Anup Narayan Singh & @sahharil ahmad: I have sent you messages directly on the queries you made.

@Jean-claude Bünzli: thank you for the feedback. And you’re absolutely right – the whole “rare elements / metals” vs. “rare-earth elements / metals” is definitely still an issue.

@henk mol: that’s a great question. There is a lot on this topic in the scientific literature but it can be difficult to figure out where to start with this. Depends how technical you want to get; if you can get hold of a copy, I have found a book called “Rare-Earth Iron Permanent Magnets”, edited by J.M.D. Coey and published by the Oxford University Press to be a useful reference guide on this topic. It was published in the late 1990s (and includes a few diagrams in the chapter on processing by Rex Harris, that I created :-) ).

There are some earlier papers from the late 1980s that also cover this topic in introductory detail; let me ask some of my magnetic materials research pals for some recommendations and I’ll get back to you.