Hello Ralph,
I am using Bruker D8 with LynxEye detector and multiple sample changer. Data collection is rapid. I use Bruker's Topas for Rietveld analysis when quant is needed. It is true that if samples are similar it is quick enough to run multiple traces through, but I find that in the real world with geological samples there is always some variation which requires extra identification work and some more care in the fitting. You need to have identified every component, and have a structure that the program can work with. I recently did a small job of six samples which had similar but slightly variable mineralogy (between five and nine phases), Starting from scratch using EVA for identification and Topas for quant this took me 2 1/2 hours work at the PC.
I am very happy with the D8 system, like Ross we have a 90 position sample changer and were using three cassettes, but on the back of a larger job we getting a full complement to all six.
Regards
Ian Slipper
-----Original Message-----
From: Support and use of X-ray diffraction instrumentation [mailto:[log in to unmask]] On Behalf Of Ralph Bottrill
Sent: 13 August 2010 06:11
To: [log in to unmask]
Subject: Re: maximum XRD throughput
Hi Ross
It's a bit uncertain but I suspect sample types will be pretty variable.
I hear mixed reports on Rietveld - some say it takes a day/analysis?
regards
Ralph Bottrill
Senior Geologist, Mineralogist and Petrologist
Metallic Minerals & Geochemistry
Mineral Resources Tasmania
PO Box 56, Rosny Park TAS 7018
Phone: 61 3 6233 8359, Fax: 61 3 6233 8338
Email: [log in to unmask] or: [log in to unmask]
-----Original Message-----
From: Support and use of X-ray diffraction instrumentation [mailto:[log in to unmask]] On Behalf Of Ross Williams
Sent: Thursday, 12 August 2010 14:27
To: [log in to unmask]
Subject: Re: maximum XRD throughput
Hi Ralph,
For both cases it really does depend on how much variation in samples and what information you actually want.
If you are doing quantitative XRD for process control or samples within the same ore-body, ie very similar samples, looking for changes in concentrations and occasionally different phases, you can automate the Rietveld quantitative phase analysis to be conducted on each diffraction pattern as soon as it is measured by the instrument while the next sample is being measured - refinements usually take less than 1 minute of computation on a modern computer. The results could be automatically written to a text file, such that it would be readable in excel.
However in both cases when a mineral/crystalline phase that you are unfamiliar with or don't expect it can delay you significantly.
Warm Regards,
Ross
-----Original Message-----
From: Support and use of X-ray diffraction instrumentation [mailto:[log in to unmask]] On Behalf Of Ralph Bottrill
Sent: Wednesday, 11 August 2010 1:34 PM
Subject: Re: maximum XRD throughput
Ross
Many thanks for this detailed reply, it's given us a lot to think about.
I does seem we need another technician for preparation as much as a new machine.
What is the general time for interpreting standard samples with Rietveld or similar quantitating software?
It's been suggested I look into Inel, Rigaku, Thermo and other XRD systems, especially if readily available in Australia - any suggestions welcome?
regards
Ralph Bottrill
Senior Geologist, Mineralogist and Petrologist
Metallic Minerals & Geochemistry
Mineral Resources Tasmania
PO Box 56, Rosny Park TAS 7018
Phone: 61 3 6233 8359, Fax:Â 61 3 6233 8338
Email: [log in to unmask] or: [log in to unmask]
-----Original Message-----
From: Support and use of X-ray diffraction instrumentation [mailto:[log in to unmask]] On Behalf Of Ross Williams
Sent: Saturday, 7 August 2010 11:55
To: [log in to unmask]
Subject: Re: maximum xrd throughput
Hi Ralph,
We have a Bruker D8 Advance with a Lynxeye position sensitive detector and the 90 sample changer - we actually only have 3 cassettes for it so only have half the capacity which is not a problem for us.
We find the bottle neck in for the instrument is usually sample preparation and interpretation. But this depends on the sample prep required, type of interpretation and the number of staff available.
+ For simple phase identification of minerals that have already been finely ground we could easily measure 90 samples per day with 15 minute scans, if the mineralogy of the samples was similar or well understood the identification (search/match) would probably take a few hours. Bruker have a command line (ie batch processing) search/match program that may speed this type of analysis up.
+ obviously if the samples are all different it could take much longer to perform search/match.
For quantitative phases analysis, you would probably measure for longer and it depends if the samples are all similar.
+ If the samples were all very similar ie all bauxite, we would use TOPAS in batch mode (or TOPAS BBQ for people who don't like scripts) to perform quantitative phase analysis as the data come off the instrument. When I operate in batch mode we monitor the "Goodness of fit" and Durbin Watson statistic, if it changes significantly I will inspect the Data/Simulation/Difference plots for that pattern.
+ If the sample were all different this analysis would be your bottle neck.
Warm Regards,
Ross
+++++++++++++++++++++++++
Ross Williams
PhD candidate / XRD Training Coordinator
Centre for Materials Research
Department of Imaging and Applied Physics
Curtin University of Technology
GPO Box U1987 Perth WA 6845
Western Australia
Phone: +61 (0)8 9266 4219
Fax: +61 (0)8 9266 2377
Email: [log in to unmask]
-----Original Message-----
From: Support and use of X-ray diffraction instrumentation [mailto:[log in to unmask]] On Behalf Of Ralph Bottrill
Sent: Friday, 6 August 2010 11:00 AM
Subject: maximum xrd throughput
We have been asked to look at setting up a new XRD facility for rapid analysis of bulk miscellaneous rock samples for core logging.
The new Panalytical and Bruker systems can load and auto-run up to 90 samples, but what is the likely maximum number of samples you could prepare, run and interpret in a day? We have an old manual system and don't know if the new auto-interpretation software is reliable enough without a lot of manual checking?
Any recommendations are welcome.
regards
Ralph Bottrill
Senior Geologist, Mineralogist and Petrologist
Metallic Minerals & Geochemistry
Mineral Resources Tasmania
PO Box 56, Rosny Park TAS 7018
Phone: 61 3 6233 8359, Fax:Ã'Â 61 3 6233 8338
Email: [log in to unmask] or: [log in to unmask]
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