Hi Jean-Marc Gravity separation is probably a thing to keep going with, but with heavier liquids.
There is a program here (CENTRISET - https://woodshole.er.usgs.gov/openfile/of2005-1001/htmldocs/vbasic_software.htm) that will help you in calculating settling times for gravity and centrifuge separation given liquid temperature and viscosity, and particle size and density. Note: I have zero experience with this, but it does seem feasible. Matthew On Thu, 1 Jul 2021 at 17:21, Jean-Marc Joubert <joub...@icmpe.cnrs.fr> wrote: > Dear all, > I have another question more or less related to the topic of clay sample > preparation. > I would like to separate the coarse from the fine grains in a powder > obtained by crushing. > This is in order to get the finest (1 to 5 µm) grains without having to > introduce too much strain by a too energetic crushing. > From the SEM analysis this fine particles are indeed present in the powder > but mixed with larger particles (~30 µm). > Sieving in this size range is probably not very efficient. > I considered using settling in alcohol or acetone but the density of the > materials is very large (~7, it is an intermetallic compound) so that all > the particles fall very fast to the bottom. > I wonder if somebody has any advice. > Thanks in advance. > /Jean-Marc > > > > > > > Le 01/07/2021 à 09:30, Kemp, Simon J. a écrit : > > Hi Matthew, > > > > Welcome to the wonderful world of clay mineralogy ! > > > > Separating the clay (typically <2 um) by gravity settling is actually > preferable to centrifuging, as you can more easily check for flocculation. > [If this is a problem add some drops of sodium hexametaphosphate (‘Calgon’) > solution.] At BGS, we dry our isolated <2 um fractions right down in a > moisture extraction oven (set at 55degC), homogenise and then resuspend a > known amount (¬80 mg) to produce a consistently thick oriented mount. > > > > If you are not aware of it – Moore & Reynolds (1997) is the bible for clay > preparation and analysis – very easy to follow. > > > > Moore, D.M. and Reynolds, R.C. 1997*. X-Ray Diffraction and the > Identification and Analysis of Clay Minerals, Second Edition.* Oxford > University Press, New York. > > > > Best regards, Simon > > > > *Simon Kemp* > > Senior Mineralogist > > > > *p *+44 (0)115 936 3448 > > *e *s...@bgs.ac.uk > *w *www.bgs.ac.uk > > > > British Geological Survey | Nicker Hill | Keyworth | Nottingham NG12 5GG | > UK > > > > > > Profile <http://www.bgs.ac.uk/staff/profiles/0778.html> | *Twitter > <https://twitter.com/SimonKempBGS>* | Research Gate > <https://www.researchgate.net/profile/Simon_Kemp2> | Google Scholar > <https://scholar.google.co.uk/citations?user=UcipPfUAAAAJ&hl=en> > > > > > > *From:* rietveld_l-requ...@ill.fr <rietveld_l-requ...@ill.fr> > <rietveld_l-requ...@ill.fr> *On Behalf Of *Matthew Rowles > *Sent:* 01 July 2021 05:26 > *To:* RIETVELD_L Distribution List <firstname.lastname@example.org> <email@example.com> > *Subject:* Clay sample preparation > > > > Hi all > > I’m gingerly venturing into clay analysis. > > I’ve done previous analyses on pre-separated clay fractions by > resuspending the clay in a little ethanol and dripping onto a Si wafter to > make an oriented mount (which is then also successively glycolated and heat > treated). > > I have some upcoming work which will necessitate creating the clay > fraction. > > I don’t have a centrifuge, so I have to separate the clay fraction by > settling. The USGS methodology looks like a good method to follow: > https://pubs.usgs.gov/of/2001/of01-041/htmldocs/methods/decant.htm > > > After I’ve suctioned off the clay suspension, what is the best way to get > at the clay? Leave it settle more? Evaporate the water? > > (I’m also in the middle of commissioning a spray-drier, so that will help > with the random mounts.) > > Thanks > > Matthew Rowles > This email and any attachments are intended solely for the use of the > named recipients. If you are not the intended recipient you must not use, > disclose, copy or distribute this email or any of its attachments and > should notify the sender immediately and delete this email from your > system. UK Research and Innovation (UKRI) has taken every reasonable > precaution to minimise risk of this email or any attachments containing > viruses or malware but the recipient should carry out its own virus and > malware checks before opening the attachments. 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Opinions, conclusions or other information in this > message and attachments that are not related directly to UKRI business are > solely those of the author and do not represent the views of UKRI. > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Please do NOT attach files to the whole list <alan.he...@neutronoptics.com> > <alan.he...@neutronoptics.com> > Send commands to <lists...@ill.fr> <lists...@ill.fr> eg: HELP as the subject > with no body text > The Rietveld_L list archive is on > http://firstname.lastname@example.org/ > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > > -- > Jean-Marc Joubert > Institut de Chimie et des Matériaux Paris-Est > UMR 7182 CNRS-Université Paris-Est Créteil > 2-8 rue Henri Dunant, 94320 Thiais, France > Lab: https://www.icmpe.cnrs.fr/ > phone/fax: 33 1 49 78 13 44/12 03 > Researcher ID: A-1259-2013, ORCID: 0000-0001-7266-1850 > email : joub...@icmpe.cnrs.fr > personal page: https://www.icmpe.cnrs.fr/annuaire/joubert-jean-marc/ > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Please do NOT attach files to the whole list <alan.he...@neutronoptics.com > > > Send commands to <lists...@ill.fr> eg: HELP as the subject with no body > text > The Rietveld_L list archive is on > http://email@example.com/ > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > >
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