Procedure for Reclaiming Heavy Liquids AGES Lab Below are the ...

Procedure for Reclaiming Heavy Liquids
AGES Lab
Below are the steps we use to reclaim MEI and LST after using it to separate
out specific minerals. These are not the only ways to separate out these
liquids, however, after trying multiple methods, we have found these to be
the best. Feel free to contact us with any questions
(epierce@ldeo.columbia.edu, mesko@ldeo.columbia.edu ).
MEI Reclaiming Process
Below are steps that should be followed in order to reclaim MEI from the
MEI/Acetone mixture that is produced when performing heavy mineral
separations. Since water is immiscible in MEI, and since acetone dissolves
in water, adding water to the MEI/Acetone solution will cause the acetone to
dissolve in the water, and to float to the top.
You will need: Separatory funnel (500 mL, or 1000 mL if possible);
stopcock; ring stand to hold funnel; rubber stop for top of funnel, squirt
bottle of acetone; small (200 mL) glass beaker for collecting clean MEI;
small (200 mL) beaker for collecting the MEI/water+acetone interface; large
(1000 mL) beaker for pouring MEI/Acetone mixture into the separatory
funnel; large (1000 mL) beaker for pouring DI water into the separtory
funnel; plenty of DI water; a glass stir rod; container to place reclaimed MEI
in; hydrometer for testing density of reclaimed MEI; waste container for the
acetone/water solution (should be labeled as 80% water, 20% Acetone,

2. Label your beakers (according to sizings above) as ‘Clean MEI’, ‘DI
water’, ‘MEI/Acetone for Reclaiming’, ‘Acetone + Water’.
3. Pour ~200 mL (400 mL if using a 1000mL funnel) of the
MEI/Acetone solution into the appropriate beaker. Ensure that the
stopcock is in the closed position. Pour the solution into the top of the
separatory funnel. Do NOT place your ‘Clean MEI’ beaker under the
funnel in case you spill any of the mixture while pouring.
4. Pour some DI water into a beaker. Use this beaker to then pour DI
water into the funnel; this will stir the up the MEI/Acetone solution.
Fill the funnel, and use a glass stirring rod to further mix the two
solutions.
5. Rinse the stirring rod with acetone into the ‘MEI/Acetone for
Reclaiming’ beaker and dry with a Kimwipe. Place the rubber plug in
the top of the funnel.
6. Allow for ~ 20-30 minutes for separation of the MEI from the
Acetone/Water. The MEI should be clear when the separation is
complete (not cloudy).
7. Once the solutions have separated, you will empty the funnel in 3
steps. It is important to keep the rubber stopper in the top of the
funnel for the first two steps, as it keeps the flow rate to a minimum:
a. Place the ‘clean MEI’ beaker under the funnel. Open the
stopcock and allow the clean MEI to flow until you are close to
the MEI/Acetone+water interface (~ when there is MEI only in
the narrow tip of the funnel above the stopcock). Then stop the
flow. Pour the clean MEI into the appropriate container.
b. Place the ‘MEI + Water/Acetone’ beaker under the funnel.
Open the stopcock and allow to flow until the MEI and the first
of the Water/Acetone mixture has been emptied. Pour this into
the ‘MEI/Acetone for Reclaiming’ beaker (this will be
processed again in the next step; by doing this we only loose
that ‘interface’ of MEI and Water/Acetone in the very last step).
c. Place the ‘water and acetone’ beaker under the funnel and now
drain the funnel, with the rubber stopper now removed. You
will have to lift the funnel at the end so that it is not sitting in
the waste solution. Remove the beaker from the stand; close
the stopcock; pour the acetone/water solution into the waste
container.
8. You are now ready to repeat steps 1 through 7. Do this until you have
reclaimed all of your MEI.

9. Now test the density of your MEI. MEI is generated with a density of
3.32 g/cc. We use this for separating zircons (4.6 g/cc) from apatite
(3.22 g/cc). A minimum density of 3.3 g/cc is allowed. If your MEI is
not dense enough, there is still acetone in the mixture, and you will
have to reprocess all of the MEI again.
10. Once finished, all glassware must be cleaned; anything that had even
trace amounts of MEI in it must be rinsed with acetone; put these
washings into one of the ‘MEI/Acetone for Reclaiming’ containers
you just emptied. This MEI will be processed next time.
LST Reclaiming Process
Below are steps that should be followed in order to reclaim LST of
appropriate density from the dilute LST waste water that is produced
when performing mineral density separations. LST contains hydrated
crystals of lithium heteropolytungstates. Wear goggles to avoid contact
with eyes.
You will need: 2000mL filter flask; 2000mL beaker; vacuum pump,
vacuum tube; drying oven; 100mL graduated cylinder; stirring rod;
deionized water; bottle for storing reclaimed LST; precision hydrometer
suitable for heavy liquids; nitrocellulose membrane filter paper (0.22µm
GS); and a glass vacuum filtration assembly consisting of: glass funnel
top, glass frit base, clamp, and appropriately-sized rubber stopper with
hole large enough to accommodate the tube on the glass frit. (See image)
1. Funnel
2. Clamp
3. Base (glass frit)
4. Rubber stopper
1. Connect your 2000mL filter flask to your vacuum pump using the
vacuum tube. This will initially store your filtered LST. Set the
glass vacuum filtration assembly on top of the filter flask. Next,

place a sheet of nitrocellulose membrane filter paper between the
funnel and glass frit. Clamp securely in place.
2. Pour the unfiltered LST solution into the funnel. Then, start the
vacuum pump. Filtered LST will now begin collect in the flask.
3. Continue to add unfiltered LST to funnel while monitoring the
filter paper. Filter paper will have to be replaced about as
frequently as once per every 1 and ½ funnel fills. The filter paper
will start to turn tan and the flow of LST will slow when paper
needs to be replaced. Turn off vacuum pump before replacing the
filter paper.
4. Once a suitable amount of filtered LST has been collected, shut off
the vacuum pump. Pour the filtered LST into the 2000mL beaker.
Label it “filtered LST”. Then, place the beaker in the drying oven
to evaporate off the excess water. You will want to evaporate the
LST down to a density greater than your target density, so you will
then be able to add deionized water in small increments to dilute
the LST to the proper density. If crystals are forming in the warm
solution, then the LST is saturated and too much water has been
evaporated off.
5. Once you have evaporated off the excess water, remove the beaker
from the drying oven and allow the LST to cool to room
temperature.
6. Fill your 100mL graduated cylinder to about 100mL. Use the
precision hydrometer to measure the density of the LST in the
graduated cylinder. Then, pour that LST back into the beaker. Add
a small increment of water to your LST. Stir vigorously for a few
minutes until the solution is well-mixed.
7. Repeat step 6 until you reach your desired LST density, like
2.85g/mL or 2.64g/mL. If you overshoot your desired density,
place the beaker back into the drying oven and start back at step 5.
8. Finally, with your LST reclaimed at your desired density, pour it
into your bottle labeled with the achieved density for storage at
room temperature.