To the best of my knowledge, XRD can determine the presence of special mineral in the soil.
Dear Mr. Sangsefidi:
Use the XRD Rietfeld quatification in combination with XRF and CEC (cation exchange capacity) for swelling clay minerals.
Best regards
H.G.Dill
Dear Professor Dill,
Thank you for your response.
Could you introduce me any reference?
Thanks again for your time.
Kind regards,
Ebrahim Sangsefidi
There is every year a competition (Reynolds cup) where the most experienced groups are doing this. Mainly clay minerals. You perhaps find there very specific information or at least the impression that dealing with clays is a real challenge.
http://www.clays.org/SOCIETY%20AWARDS/RCintro.html
Ebrahhim,
Try the following references for XRD and feel free to contact me direct if you wish to discuss.....
Amaral, PM, Cruz Fernandes, J & Guerra Rosa, L 2006, ‘A comparison between x-ray diffraction and petrography techniques used to determine the mineralogical composition of granite and comparable hard rocks’, Materials Science Forum, vols. 514-516, pp. 1628-1632.
White, G, W 2015, Systematic Diagnosis of Factors Leading to Cyclic Shear Creep of Airport Asphalt Surfaces, A Dissertation submitted to the Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, for the Award of Doctor of Philosophy, August.
I also have a paper under peer review that I am happy to send to you directly.
Cheers,
Greg
For soils the most simple, effective and antique technique for quantifying the amount of clay minerals is sedimentation in water. Place 1 g of soil in a beaker and sonicate during several minutes. Later place the suspension in a 1 liter glass cylinder and agitate with vertical movements of a perforated piston, and let the suspension be settled. Then the fraction of suspension over certain height is collected, centrifuged, dried and weighted. The clay fraction is the relation of this weight to the initial 1 g.The time and height you must apply are published in classic books for clay minerals, and depend of density of clay minerals present in the sample and the cut size you consider is clay mineral; must common are 1 µm or 2 µm .
This procedure should be prior to any other instrumental technique.
I can send you some publications on XRD methods applied to clay mineral quantification. In addition the book by Moore and Reynolds is an excellent starting point.
Hello,
I would say it depends on the composition of the sample.
XRD can help to achieve semi-quantitative results but that`s not good enough, especially for clay minerals. I have examined this issue 20 years ago. So maybe the technique has strongly improved in the meantime.
1. Try to separate the clay fraction. This is not always possible.
2.You should have the chemical composition of the whole sample and if possible also of the clay fraction (e.g. XRF). If your clay minerals are for instance kaolinite and illite you can calculate the proportion by using stoichiometric data.
For instance illite. You can calculate the proportion via potassium (K0.65Al2.0[Al0.65Si3.35O10](OH)2) if you have no other potassium-rich minerals in the sample (see XRD). Then you can go on with other cations or anions. Kaolinite = Al2(Si2O5)(OH)4 - use the Al-content. In case you have other Al-rich minerals, it will be difficult but not impossible.
This works fine if the sample composition is not too complex and by far better than XRD only.
In my calculations differences of approx. 2% in relation to 100% of the sample indicated another mineral phase which was not visible in the first run in the XRD-diagram - below detection limit of XRD. That was a good possibility of control.
If you have a lot of mixed layer minerals in the sample, a quantitative calculation via stoichiometry is not possible in most of the cases.
Best regards
Mario Wipki
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