Clay Separations focus on separating the clay size fraction, <2 µm, from the rest of the material. In order to get only that size fraction we prepare the sample in a different way compared to bulk analyses. Do not freeze dry samples waiting for clay separations.

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Technique for clay separation requires the use of acetic acid. To dispose acid solution properly and environment-friendly, use the black sink in the Chemistry Lab or in the Thin Section Lab (Figure XX4). These sinks are directly connected to a specific container in the ship dedicated to acid treatment. DO NOT USE OTHER SINKS !!! Use flowing water to dilute the solution.

Figure 4. Black sink to dispose acid solution

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1. After removing the supernatant (after the last wash), add ~25 mL of a 1 % Borax solution into to the centrifuge tube (Figure 9, Step #8). Borax prevents the sample from flocculating. Too much Borax however will increase flocculation. 
2. Put the tube into the bottom clamp inside the dismembrator case Position the sample with the sonicating probe abut half-way into the sample material. Use the clamp to hold the tube in place (Figure 9, Step#9). Put the probe into the top clamp and the sample tube into the bottom clamp. Adjust the positions so the probe goes into the tube. The probe should be about half-way into the sample material without touching the sides of the tube. The probe releases a lot of energy, and if it is touches the sides it will heat up the tube and the sample.The probe should not be touching the sides of the tube or the release of energy from the probe will melt the plastic tube. 
3. When satisfied with the positioning, flip the "ON" Switch (Figure 10, arrow A).  The settings are already set to our needs: Mode = Continuous, Amplitude = 65 (Figure 10). To run as is, press the "Test" button (Figure 10, arrow D), the screen will display 'rdy' for 'ready'.then, press the "Start" button (Figure 10, arrow E)when it is ready for use. Alternatively, if you select Mode = Time (min/sec), the probe will stop automatically after 1.5 minutes. If you need to change a setting, press the "Mode" button (Figure 10, arrow B) and then the "Set" button (Figure 10, arrow C). From these two panels, you have access to the power, time, and displayed units. For more information, reference the Manufacturer Manual located in the side pocket of the dismembrator case (Figure 10).
4. Press the "Start" button on the probe power supply (Figure 9, Step #10 and Figure 10, arrow E). If the material does not appear to be circulating throughout the whole tube or the tube is heating up, adjust the probe position and start the dismembration over.circulating throughout the whole tube or the tube is heating up, adjust the probe position and start the dismembration over. Allow the sample to circulate for at least 1 minute, then press the "Stop" button (Figure 10, arrow E). Remove the sample from the clamp. Wipe the probe with a Kimwipe, then clean with isopropyl alcohol and dry with a Kimwipe.
5. Leave the sample to settle for about 12 hours on the benchtop After the suspension, settle down the tube for about 12 hours (Figure 9, Step #11).

Figure 9. Adding Borax and Suspending Material with the dismembrator. Make sure to adjust the probe half-way into the sample material

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Figure 10. Dismembrator set up and Probe with power source. Dismembrator power source control Panel. (A) On/Off switch (B) Start button (C) Set button (D) Mode button (E) Start/Stop button

Standard IODP Clay Separation Method: Not for Semi-quantitative Analysis

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Figure 14. A. Dessicator and oven for glycolation. B. Dried sample preparation after dessication.

Additional Clay Treatments before Scanning

Treating with Ethylene Glycol

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If the dismembrator does not start the program after pressing the button "Start", i.e., if the screen still displays 'P  0' (Power=0) and not 'rdy' (Ready), press the "Reset" button, then press "Test" and finally "Start". The dismembrator should clear the error and starts start the program normally. Power on the display screen should be 'P  11' when a sample is vibrating. The cause of this error is unknown and happens when the dismembrator is turn turned on.

References

Jackson, M.L., 1956. Soil Chemical- Analysis Advanced Course by Hsueh-Wen Yeh, Hawaii Institute of Geophysics, 1980.
Moore, D.M., and Reynolds, R.C., Jr., 1989. X-ray Diffraction and the Identification and Analysis of Clay Minerals: New York (Oxford University Press).

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XRD Sample Preparation Clay Separations - September 27, 2022