Bentonite at work

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Joined: 12 Mar 2019, 14:44
Location: Texas, US

Bentonite at work

Post by BrentBo » 12 Mar 2019, 17:28

Hello everybody! First off, thanks Steve for the equipment! I still have a big learning curve but I think i'm starting to get the hang of it. Glad to be a part of the community!

Working in the oil and gas industry we use bentonite quite a bit and store it in silo's that hold 20 tons. I have a Polimaster scintillator and decided to take it to work one day and come to my surprise the device went crazy near those silo's. Never knew bentonite had some radioactivity to it! Looking at the spectrum, I guess we're looking at your typical uranium spectrum? The sample I brought back to my office/lab seem to lose radioactivity leading me to think the Polimaster is picking up on the radon build up in these silo's.

The spectrum isn't too clean because I couldn't take my whole lead castle with me to work. I had to opt to rolling some lead sheeting around the probe.

Next project tomorrow will be getting a sample of some of these shale cuttings that are coming from 9,000 feet underground!
Bulk Bentonite plot.png
Bulk Bentonite plot.png (87.58 KiB) Viewed 480 times

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Posts: 30
Joined: 20 Feb 2019, 17:36
Location: Utah (USA)

Re: Bentonite at work

Post by isoenzyme » 24 Mar 2019, 10:08

Hi BrentBo:

Thanks for sharing the bentonite spectra - chemically bentonite is Al2O3-4SiO2-H2O (or H2Al2O6Si) which doesn't give much to see with a gamma spectrometer. These kinds of "clays" are quite susceptible to contamination by radium, strontium and etc. Many of the peaks in your spectra look like NORM (which might be expected at a drilling site). If you take more data on this sample I'd be interested to see it!

Which software are you using to collect your spectra?

Thanks, isoenzyme
(Christopher Lloyd)
Christopher Lloyd
Salt Lake City, Utah (US)

Setup: Modified GS-STANDUP-20 with GS-USB-PRO
Primary Detector: GS 2" x 2" CsI(Tl)

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Steven Sesselmann
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Joined: 27 Apr 2015, 11:40
Location: Sydney

Re: Bentonite at work

Post by Steven Sesselmann » 24 Mar 2019, 17:53


The peaks in your spectrum look like Thorium to me, try moving the calibration a bit to the left so the second peak sits at 238.6, then see if the other peaks line up.

Steven Sesselmann | Sydney | Australia | | | |

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