Grease Table Experiment

arizau

Bronze Member
May 2, 2014
2,479
3,854
AZ
Detector(s) used
Beach High Banker, Sweep Jig, Whippet Dry Washer, Lobo ST, 1/2 width 2 tray Gold Cube, numerous pans, rocker box, and home made fluid bed and stream sluices.
Primary Interest:
Prospecting
In that sample, it had other metals than just iron, so acid would not be a good idea. Part of it was fine zircon/reidite sand from the Rock Elm disturbance with a SG of 7. Fanning that stuff off the gold is really tricky, as it wants to move less than the iron sand, and the gold tends to be round there, so the zircon hitting it makes it move. I'm also limited in the chemical side of things. I have the apparatus, just not the chemicals to go with. A strong base might soponify the whole mass and make things even worse to recover. Gasoline or toluene, maybe MEK or acetone might work better than alcohol at dissolving the grease, but you will have a fire hazard. I'd rate this as being worse than having to deal with mercury coated gold.

The gold used in this experiment did not get captured by my miller table, so it is very hard stuff to capture. The grease caught a good 60-70% of it. Had I run straight concentrate, the grease would have captured everything that the miller table would have caught plus the 60-70% that it wouldn't catch. So you can't say that it's a totally bad method for recovery. It just takes a lot of screwing around to do it. Any gold under #300 will not be caught by this, and if it is, it's just luck. So fish oil and burlap is BS for micron gold.

Recovery wouldn't be so bad if a simple method of degreasing can be found. With the Vaseline being paraffin, burning it off might be the easiest option.

If you want to have some fun experimenting and getting dirty and finding a new method, HAVE FUN! Otherwise, STAY AWAY until this method can be refined.

I think thinly spreading the vaseline/concentrates in a baking pan and heating it on a bbq grill should/may(?) vaporize the vaseline but you have to get it hot enough! The vapor/boiling point for petroleum jelly/vaseline is about 650 degrees per this MSDS for vaseline. http://www.bmed.mcgill.ca/REKLAB/manual/MSDS/Materials List/petroleum_jelly.pdf

Search Goodguy's posts for suggested solvent(s) that will dissolve the vaseline so that they both will float up and then can be poured off. I think one of them is lighter fluid/naptha(?).

Good luck.
 

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Capt Nemo

Capt Nemo

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Apr 11, 2015
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I do have a few porcelain lab crucibles that I could just load the grease into and burn it off in. Who knows, the heat might burn off any sulfide gold in the black sand too.

I'm going to try a burn test with some depleted black sand mixed with Vaseline, and see what happens. Hopefully it's panable without any other steps.
 

arizau

Bronze Member
May 2, 2014
2,479
3,854
AZ
Detector(s) used
Beach High Banker, Sweep Jig, Whippet Dry Washer, Lobo ST, 1/2 width 2 tray Gold Cube, numerous pans, rocker box, and home made fluid bed and stream sluices.
Primary Interest:
Prospecting
I know this is an old thread and you have put your experiment to bed but a couple of questions for you Capt Nemo about your testing if you still remember. About what was the percentage gold vs. non gold particles that stuck to the grease and from that about how much of the total "greased" area was clear? What volume of material did you run in your testing?
 

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Capt Nemo

Capt Nemo

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I ran about 1 gal of miller table tailings (already hard gold to capture), and was left with about a teaspoon of cons from a 10"x10" greased area. Some was caught due to the irregularities in the grease. If it was smoother, the less black sand/zircon would have been caught. The same might have been true with the amount of water and angle used to flow the water in a sheet over all the grease.

Having a series of drops, or higher drops, might have helped the gold break the surface tension and stick to the grease better. But the gold may just be too fine to allow it. Again it becomes a matter of proportional forces between the gold and water.

I like the table as it would catch quite a bit better than the miller table and is faster, but I hate it for how it has to clean up. It's not perfect, but then, what is?
 

arizau

Bronze Member
May 2, 2014
2,479
3,854
AZ
Detector(s) used
Beach High Banker, Sweep Jig, Whippet Dry Washer, Lobo ST, 1/2 width 2 tray Gold Cube, numerous pans, rocker box, and home made fluid bed and stream sluices.
Primary Interest:
Prospecting
I ran about 1 gal of miller table tailings (already hard gold to capture), and was left with about a teaspoon of cons from a 10"x10" greased area. Some was caught due to the irregularities in the grease. If it was smoother, the less black sand/zircon would have been caught. The same might have been true with the amount of water and angle used to flow the water in a sheet over all the grease.

Having a series of drops, or higher drops, might have helped the gold break the surface tension and stick to the grease better. But the gold may just be too fine to allow it. Again it becomes a matter of proportional forces between the gold and water.

I like the table as it would catch quite a bit better than the miller table and is faster, but I hate it for how it has to clean up. It's not perfect, but then, what is?

It seems to me that the recovery process could be more easily achieved. My thought (only partially original) to make it easier is to drain the heated solution and additional heated water through a coffee filter. The drained filter and contents can be heated outdoors in a vented container until the filter burns and any remaining vaseline vaporizes or burns off. Pan, or screen and pan, the remains for gold recovery.
 

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Capt Nemo

Capt Nemo

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Apr 11, 2015
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Oshkosh, WI
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The Vaseline melts at maybe 110 degrees, which is easily doable with domestic hot water. When liquid, the Vaseline drops everything making it easy to pour the bulk off, but it does hang on to things like any organic matter or dust that accumulated. To reuse, you would want to filter the liquid grease. It's kinda like working with candle wax, only lower in temp.

If going the burn route, I'd melt the grease and pour the bulk off, and then burn the dregs.
 

johnedoe

Bronze Member
Jan 15, 2012
1,489
2,239
Oregon Coast
Detector(s) used
White's V3i, White's MXT, and White's Eagle Spectrum
Cleangold sluice & prospectors pan, EZ-Gold Pan, and custom cleanup sluice.
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Other
I am amazed you have continued to test this for so long...
You have done a great job....Interesting too.
 

Goldwasher

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May 26, 2009
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Sailor Flat, Ca.
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SDC2300, Gold Bug 2 Burlap, fish oil, .35 gallons of water per minute.
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Sounds about as fun as herding cats.
 

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