Super concentration before panning, miller table or blue bowl recovery of fine gold

arizau

Silver Member
May 2, 2014
2,516
3,941
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
Here is a way to greatly reduce the volume of your pre-classified concentrates (super concentrate them) before you begin to process them by panning, etc. by using a large funnel*, rubber cork, eye screw, length of wire and a short section of pvc pipe.

Procedure:

Insert the cork, attached to a piece of stiff wire, into the top of the neck of the funnel. Make sure there is room to form a small chamber in the neck below the natural slant of the funnel main wall.

Add concentrates (avoid overloading) and water (as much as your funnel can hold) and swirl the funnel to allow the gold to seek the bottom in the slurry. When you stop the gold and other heavies will be the first to settle and most if not all of it into the chamber or centered above it. Closely classified feed pretty much assures this.

Hold level and allow time for the water to stop spinning then thread the wire through the pipe**. Note: It is easier to do this and the previous step if you drill a hole in a board and place it on a catch container. Stir it to a vortex with whatever you choose.

Kind of ratchet the pipe and bore straight down until it bottoms out on the main funnel wall. At this time the pipe will likely be held loosely in place by the surrounding cons and water.

Hold the pipe in place and pull the cork out with the wire to let the "core" (super concentrated material in the pipe) drain into a tall sided container to avoid splashing and overflow. Flush the pipe with water if it did not fully drain...it should. At this point you will have reduced the total amount of concentrates to process by up to about 75% or more.:icon_thumleft:


The tails (what is left in the funnel surrounding the pipe) are almost surely barren of gold but save it to reprocess later just in case you don't trust the method.

If your starting point is with a large amount of concentrates (bucket or buckets)*** then you will end up with a still overly large amount of super concentrates that can be further reduced by repeating the process with them. Also you can re-process your tails just to be sure you got it all.

Heavy pans!


* One with vertical sides above the cone is best.
** The pipe opening should be larger than the funnel neck and it should be beveled to create a tight flat fit against the main funnel wall!
*** Use a large funnel. Here is a 10" funnel that I am using. Got it at a local home brew/wine making store. https://www.homebrewing.org/10-Funn...MMU8yCncxcB8KH9RpTClpn2R7JpvhUwhoC7WwQAvD_BwE
 

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This much details explained with a MacGyver styled beer funnel; OK, got me interested for sure.

Any pictures,
 

No pics...I have repurposed the funnel into another "MacGyver'ed" device for more or less the same purpose but now as a primary concentrator for fairly large volumes of gold bearing ocean beach sand. Still to be finished and tested but I will post pics if it works.
 

Miller table fast easy & no junk ,minus 40 mesh :) 016.JPG
And idiot proof :)001.JPG
 

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That’s still pretty big gold there (your -40), show me the -100 or -125 and I’ll be Impressed.
 

That’s still pretty big gold there (your -40), show me the -100 or -125 and I’ll be Impressed.

You asked.Minus 100 under magnification "pin head" and smaller 003.JPG
- 100 mesh,maybe a thousand of them NO problem for the Miller :)001.JPG004.JPG
 

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Minus 125 on the Miller.Holding steady in place w/water flowing over them :)008.JPG
So small that w/o jet-dry they float when placed in a vial of water005.JPG
 

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That’s the stuff!
 

No pics...I have repurposed the funnel into another "MacGyver'ed" device for more or less the same purpose but now as a primary concentrator for fairly large volumes of gold bearing ocean beach sand. Still to be finished and tested but I will post pics if it works.

Re the above...My current project is for processing ocean beach sands for gold concentration. Typical beach sand is usually at or below 100 mesh and so is the gold.

I affixed a plugged 10" funnel into a bottomless 5 gallon bucket making it into a small cone tank. I drilled a hole near the bottom of the funnel cone and pump water through it horizontally around the side to create circular flow similar to stirring it with a paddle creating a vortex of a sort to keep sand feed in a slurry so that gold has a chance to settle in the dense slurry. Feeding will be metered through another funnel to the center of the container exiting fairly deep in the slurry. Preliminary testing is positive that gold (hopefully most or all (?) settles through the rotating slurry to a level with or below where the water is injected thus the gold is protected and concentrated. I am in hopes that waste sands can be cycled out of the tank via an overflow hole above the anticipated gold concentration zone to make it a continuous operation allowing constant feeding. The slurry load has to stay fairly minimal, about a pan full or less, otherwise the sheer weight of it will slow or stop the rotation of it and not allow the gold to settle through it.* Final concentrates can either be drained or washed out of the container at the end of the day. Only testing will tell...more later.

*I'm using an 800gph pump but a higher capacity pump may be in the offing to facilitate a higher slurry load/feed rate.
 

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Ok! I think I am on to you Arizau. I think I screwed around with the same concept which I learned from a you tube video.

If you take a five gallon bucket, place a gallon of concentrates into it, give some rapid swirling with a stick. When you swirl it all the material that is denser than water will migrate to the outside bottom of your bucket. Then let it settle, the densest material will be the first thing to stop swirling. When it starts to slow down the gold will concentrate itself in the center of the bottom of the bucket.

Now for only the trick part of the magic trick- getting the center bottom of the bucket out without disturbing the rest of the pile.

The best I came up with, though I have not built it, is a shallow removable cup, maybe about 2"-3" in diameter, that screws under a hole center bottom of my 5 gallon bucket. Swirl, let it stop, slide a piece of sheet metal under the pile to separate the wanted from the unwanted and keep the unwanted dirt and water in the bucket, then unscrew the cup and pan its contents.
 

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Ok! I think I am on to you Arizau. I think I screwed around with the same concept which I learned from a you tube video.

If you take a five gallon bucket, place a gallon of concentrates into it, give some rapid swirling with a stick. When you swirl it all the material that is denser than water will migrate to the outside bottom of your bucket. Then let it settle, the densest material will be the first thing to stop swirling. When it starts to slow down the gold will concentrate itself in the center of the bottom of the bucket.

Now for only the trick part of the magic trick- getting the center bottom of the bucket out without disturbing the rest of the pile.

The best I came up with, though I have not built it, is a shallow removable cup, maybe about 2"-3" in diameter, that screws under a hole center bottom of my 5 gallon bucket. Swirl, let it stop, slide a piece of sheet metal under the pile to separate the wanted from the unwanted and keep the unwanted dirt and water in the bucket, then unscrew the cup and pan its contents.

The video you saw is here and his collection is easy. http://www.treasurenet.com/forums/gold-prospecting/442847-two-bucket-method.html
 

Here is the problem with Miller tables and blue bowls. First they are slower than lasses in winter :) Next you can't pan or recover what you can't see!!!!! Gold less than 100 mesh and for sure less than 150 mesh cannot be seen with 20-20 vision!!! And friend, most gold in that creek is less than 100 mesh!!!!! You have only 2 methods, amalgamation and smelting. Either will work very well!!!! Or at least they have for the last 6000 years ;)

And before you get all "enviromental" take into account the liberals in California. Last year Jerry Brown and company along with PG&E burned 1,893,913 acres. That is 82,498,850,280 square feet of earth!!!! Millions and millions of tons of sulphides, cyanide, and arsonic were released into the air! California is very rich in cinibar so millions of metric tons of mercury were evaporated from the rock and sent into the air. All the gold miners in the world couldn't do that in 100 millennia!!!!
 

Millions of metric tons of mercury? Thats a little far fetched there.
 

So you think floating gold is fine?....LOL

Here is some fine gold... So fine the static charge causes it to stick to the sides of the vile.

Give it a tap and most of it falls back to the bunch.... That is 300 mesh +/- by the way.

IMG_1369.JPG IMG_1370.JPG
 

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