Beaker of foils dropped on soil

[circaeng]

Hi

I have been a member here for a couple of months. My first batch of foils in AP worked really well a couple of weeks ago.

So I decided to do a second one but this time, on a very windy day, the beaker outside on a table fell on its side on the soil. I was able to shovel all the dirt in a container, about a bucket full to make sure I got it all.

I decided to turn this misadventure into a learning experience and try to get some of it back and learn panning techniques.

But before I do anything with it, I wanted to get your input on how you would tackle this.

What fell on the soil: An unbroken 2 litre beaker with about one inch of HCL and probably about 2 grams of very very fine foils in it, fairly clean since I had just finished boiling them in HCL to remove any copper left over after normal AP process.

The soil itself is top soil with lots of organics, not much sand or clay.

Thanks

Pat

 

[FrugalRefiner]

I'd probably try a gold pan first. Work over a large tub of some kind, so everything you pan off is not lost in case any escapes the pan. I'd add a few drops of dish washing soap to keep the floaters to a minimum. If it doesn't work, you'll still have everything in the tub.

Dave

 

[g_axelsson]

Panning won't work. Too much surface to weight.

I would call it a lost case and go on to the next batch.

The only real alternative for recovery would be to incinerate to get rid of the organics and then crush and leach it with something that could dissolve the fine gold.

If you hadn't already shoveled the soil in a container I would have proposed to let it dry (or even burn the patch) and then recover the gold with a vacuum cleaner (think you call it a hoover?). Since the gold would have been on top of the ground you would probably get the gold foil mixed with various organic material, but that would have been reduced quite a lot by incineration.

... just a crazy idea of mine, I have never needed to vacuum the lawn yet. :mrgreen:

Good luck with your learning experience.

Göran

 

[circaeng]

Panning won't work. Too much surface to weight.

I would call it a lost case and go on to the next batch.

The only real alternative for recovery would be to incinerate to get rid of the organics and then crush and leach it with something that could dissolve the fine gold.

If you hadn't already shoveled the soil in a container I would have proposed to let it dry (or even burn the patch) and then recover the gold with a vacuum cleaner (think you call it a hoover?). Since the gold would have been on top of the ground you would probably get the gold foil mixed with various organic material, but that would have been reduced quite a lot by incineration.

... just a crazy idea of mine, I have never needed to vacuum the lawn yet. :mrgreen:

Good luck with your learning experience.

Göran

Thanks for the suggestions guys.

I will at least try something. For me It is a hobby and it is more about the process/leanring than the end result. I always wanted to try panning/sluice. THis might not be the material to try but I have nothing to loose. One thing about the gold in it, it is more like very fine particles than foil at this point. It came from unpopulated gold plated (maybe mostly flash plated) small PCBs. I had lots and lots of those boards (30 pounds) so I practice on them. Those who have tried AP of very thinly plated PCBs know what I mean. It looks more like dust than foils . THey are easily disturbed in water and take a long time to settle. So after AP I boiled them in HCL to remove any left over copper and make them smaller/heavier. It worked, they looked like gold powder and went to the bottom of the beaker quickly.

So that is what is in the soil at this point.

For a while I have been planning to build a combination of blue bowl and sluice to try getting gold from powdered ICs (ball milled). A setup like this one: https://www.youtube.com/watch?v=h_m0xtevlpg

Would that be worth a try on this dirt bucket?

Thank You

Pat

 

[Silver Sliver]

Thanks for the suggestions guys.

I will at least try something. For me It is a hobby and it is more about the process/leanring than the end result. I always wanted to try panning/sluice. THis might not be the material to try but I have nothing to loose. One thing about the gold in it, it is more like very fine particles than foil at this point. It came from unpopulated gold plated (maybe mostly flash plated) small PCBs. I had lots and lots of those boards (30 pounds) so I practice on them. Those who have tried AP of very thinly plated PCBs know what I mean. It looks more like dust than foils . THey are easily disturbed in water and take a long time to settle. So after AP I boiled them in HCL to remove any left over copper and make them smaller/heavier. It worked, they looked like gold powder and went to the bottom of the beaker quickly.

So that is what is in the soil at this point.

For a while I have been planning to build a combination of blue bowl and sluice to try getting gold from powdered ICs (ball milled). A setup like this one: https://www.youtube.com/watch?v=h_m0xtevlpg

Would that be worth a try on this dirt bucket?

Thank You

Pat

That setup in the video looks interesting, please share your results if you try it with the powdered ICs.

Good luck!

 

[circaeng]

I will update this thread when I give it a try in a few weeks.

For those curious about the setup in the video and want to see a similar one in action here is another video : https://www.youtube.com/watch?v=-n9-4rpJAkE

Pat

 

[butcher]

Screening may help to remove larger particles, rocks,sticks, and leaves...
Incineration, would be a good idea, Wash the dirt in a solution of NaOH and rinse well first.

Melting with a little flux and a collector, may also work, depending on the type of soil, before doing so it would be a good idea to give the dirt a wash in a solution of NaOH, and rinse well with water to help remove chloride salts, and dry the dirt.

The melting may help to make the gold form small balls of gold, which would be easier to pan out of the dirt, fine gold foils or powders, although having a greater specific gravity than the dirt, tend to float easily, or to be shoved around by the heavier potion of the dirt, very fine gold powders or foils float easily, especially if any oil is involved, soap can help to break the surface tension of water, I am unsure if the fine foils trap air under them or, if they just have a larges surface area or what, but they can be very hard to pan, the dirt can trap them easily making it hard to get them to sink to the bottom of the pan and stay there as the other material is washed away. Melting them into tiny gold balls or nuggets may help.

If this was more of black dirt type garden soil, after washing with NaOH, and water to remove chlorides as dissolved salts (gold is volatile at high temperatures where chlorides are involved), and then incineration of the soil, a leach may work, many soils like in my area have a high iron (or other metal) content, so I would have to leach most of the leachable iron out first, before I could leach the gold, you may not have that problem with your soil.

Panning into a large washtub of water is a good way not to lose material.
A good way to practice panning for gold, or to learn to pan for gold is to cut small pieces of lead, say six pieces of lead cut off a chunk of lead with a pocket knife ranging in size from small to tiny, fill your pan with rocks, gravel, sand and dirt, toss in your small lead pieces in the pan and stir it up.
Now pan off the material dumping what you pan off into the wash tub of water, when you can pan off everything leaving the six pieces of lead in the corner of your pan, with most all of the black sand washed off it, you can feel confident you can pan gold, if you dump any of the six lead pieces in the wash tub with the other rocks sand and gravel you are panning off, you will just need more practice.

 

[maynman1751]

I have used a Blue Bowl and I can tell you that it won't work with these fine particles. If you do as Butcher said and try to melt them into tiny beads, then a Blue Bowl may work. You want to catch all of your 'waste' and re-run it to make sure you get all of your gold. Run your Blue Bowl over a catch bucket. The water that overflows will carry a lot of the dirt out and a second or even a third run of the material left in the bucket will help recovery.

 

[Harold_V]

Your material is akin to that which remains when processing polishing wastes from a jeweler's bench. A lot of dirt laced with values.

I see little promise in trying to recover the values by any mechanical method, including melting, as even melted, you'd have particles that are too small to be visible, thus they would be difficult to capture.

That being said, you might consider the following process.

Incinerate the dirt until there are no glowing embers when oxygen is applied.

Screen the dirt, to remove large particles, which should be free of values.

Boil the screened material with HCl, to dissolve anything that is soluble. This operation serves more than one purpose, as it will assure that when you finally dissolve the values (for recovery) that the solution will permit being filtered.

After the HCl boil, rinse the solids well with tap water, allowing the solids to settle fully before siphoning off the rinse solution. Rinse more than once, until the rinse solution is clear of color.

Dissolve the values, using an excess of aqua regia (or the solvent of your choosing). An excess will ensure that you recover all of the values.

Separate the solution from the solids, then rinse the solids with tap water until no values are detected when testing with stannous chloride.

Evaporate the solution, in preparation for final filtration and precipitation. Add a couple drops of sulfuric to the solution while evaporating, which will ensure that any lead that may be present will be precipitated as lead sulfate, and removed in final filtration.

Harold