REE are mostly concentrated in accessory minerals like allanite, monazite , apatite, xenotime in granites, where it occurs as part of the crystal structure, which is not extractable, that too when their content seems to be ppm level  in chemical analysis.

Rarely bastnasite may occur in granite which is a REE bearing mineral.

The accessory minerals like this may constitute 1-2% of the rock, in most of the cases. To economically extract REE it should be available in much higher concentrations.

Dear Dr. Majumdar,

apart from the mineralogy and the structure and grain size of the host granite which dictate the way of mineral processing it is the composition of the LREE, MREE and HREE. Neodymium, europium, terbium and dysprosium we are in short supply of but the remaining REE there is a surplus. It is especially the MREE range which counts. Excluding xenotime, almost all REE hosts predominantly contain LREE. Therefore it would be a bit of speculation to decide what REE mineral you deal with. In granites monazite, allanite, euxenite-(Y), gadolinite and samarskite-(Y) occur. Some of the minerals specialized for Y also may contain elevated MREE. Relevant concentrations are only observed in the REE-U-Nb-bearing pegmatites (in places, transitional into intragranitic deposits with Mo-W-U-Be) and Be- and Y-bearing alkaline intrusive rocks (nepheline syenite). The alkalinity of your host rock of the granite clan is decisive. Considering the alkaline igneous rocks the following figures should be kept in mind: Lovozero > 1000 Mio tonnes, grade approx. 5 % REO, Thor Lake 65 Mio tonnes, approx. 2 % REO. You see it seems to be far apart from being feasible.A mean of approx. 100 Mio tonnes is realistic.

I hope it was not too discouraging news.

With kind regards

H.G.Dill

I hope it was not too discouraging news.

With kind regards

H.G.Dill

Thanks Prof. Dill/ Dr. Latha  for answering.

My impression is that in my study plutons with an increase in grain size there is sizeable reduction in REE content; also it shows a poor value in fine porphyritic granites.

Dear Dilip,

REEs and RM-bearing minerals are rich in specific rocks such as felsic types of granites, plz refere to my book: REEs and RM-bearing minerals and their economic aspects, which is published in LAMBERT, 2014. Prof. Mohamed Th.S.Heikal

Dear Prof. Heikal,

First of all I must thank you and happy to learn that you have written a book under the title, 'REEs and RM-bearing minerals and their economic aspects, which is published in LAMBERT, 2014". Can you provide me the soft copy of your book? I am eager to see the valuable contents.

Regards

D. Majumdar

Prof., Dibrugarh University, India

Dear Prof. Diplip,

Good day. Unfortunately, I have no soft copy, only hard copies, I have. You can buy this book via Amazon agency, USA or any book stores in Europe.

Regards

Mohamed