Simple solution to fine gold recovery

johnedoe

Bronze Member
Jan 15, 2012
1,489
2,242
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.
Primary Interest:
Other
This was developed by Randy Clarkson, an expert in gold recovery designs.

A simple gizmo to help miners snag lost gold..... New gizmo could help placer miners snag lost gold | Yukon News

Also this by Randy Clarkson on fine gold recovery which is somewhat misleading in that this is mostly about commercial ops and 1" minus classification is considered fine....... The Clarkson Study Fine Gold Recovery

Here is a PDF presentation of the process....... http://www.geology.gov.yk.ca/pdf/141114_Nov1014_Grinding_for_Gold_Presentation.pdf ....... Thank you arizau for finding that PDF

Enjoy the learning.
 

Last edited:
Upvote 0
I've been looking for something for a simple way to do this.... and I just bought a wheel. LOL!
 

So, using the same concept, why wouldnt a "rock tumbler" work as well? I've never used one, but it seems to me if the revolution were fast enough, you could put some small rods in there with similar results. For about $50 bucks.
 

So, using the same concept, why wouldnt a "rock tumbler" work as well? I've never used one, but it seems to me if the revolution were fast enough, you could put some small rods in there with similar results. For about $50 bucks.
I don't think there would be enough weight to the rods to be able to do the crushing of the cons, also the rock tumbler tub is usually a hard rubber or plastic and I think the steel drum pays a significant role in the process...... But hey ya never know till ya try.
 

I don't think there would be enough weight to the rods to be able to do the crushing of the cons, also the rock tumbler tub is usually a hard rubber or plastic and I think the steel drum pays a significant role in the process...... But hey ya never know till ya try.
Thanks for the info. I see your point.
 

So, using the same concept, why wouldnt a "rock tumbler" work as well? I've never used one, but it seems to me if the revolution were fast enough, you could put some small rods in there with similar results. For about $50 bucks.

The problem likely would be burning out the tumbler motor. The weight of the iron rods might make it too heavy to easily rotate. Still, why not try it? Yes, the inside liner is rubber (which are replaceable), but I think most of the grinding comes from the rods themselves.

His tumbler looks to be about 8-10 inches in diameter. A rock tumbler is about 6" and generally not as long. Still, I think it might be worth a try. I am sure with all the research Clarkson did, his dimensions are better, but you just might get pretty good recovery with a rock tumbler. Some testing would be required to see if you need longer times (likely) and if it actually will work.
 

Read this.... He is pretty specific about what it takes to get the job done. http://www.geology.gov.yk.ca/pdf/141114_Nov1014_Grinding_for_Gold_Presentation.pdf

Yeah, I read it. You do not want to overgrind. Basically, you are using the rod mill to flatten the gold while crushing the gangue to an even finer powder. That is why they used a rod mill, not a ball mill. He does not want to powder everything, just the gangue. The gold is flatten so that it doesn't go through the sieve that lets the now finely-powdered gangue go through. So he has the very best set up, arrived at experimentally, but he gives the equation and specs for the process. Get as close as you can with a rock tumbler and experiment. Even with his equipment you have to test or you can overgrind.

I would still say, experiment, experiment, experiment with the rock tumbler if you don't have $2000 to put into a set-up like he has. Besides, he is looking at production for a large scale mine and even so emphasizes small (< 1 Kg) batches and relatively short tumble times. I can grind rock to powder with a rock tumbler. What I want to avoid is also powdering the gold--just flatten it some. Hey, what have you got to lose? Other than burning out the motor on the tumbler? :)
 

Another picture: Clarkson's Mining Tumbler.JPG
 

Yeah, I read it. You do not want to overgrind. Basically, you are using the rod mill to flatten the gold while crushing the gangue to an even finer powder. That is why they used a rod mill, not a ball mill. He does not want to powder everything, just the gangue. The gold is flatten so that it doesn't go through the sieve that lets the now finely-powdered gangue go through. So he has the very best set up, arrived at experimentally, but he gives the equation and specs for the process. Get as close as you can with a rock tumbler and experiment. Even with his equipment you have to test or you can overgrind.

I would still say, experiment, experiment, experiment with the rock tumbler if you don't have $2000 to put into a set-up like he has. Besides, he is looking at production for a large scale mine and even so emphasizes small (< 1 Kg) batches and relatively short tumble times. I can grind rock to powder with a rock tumbler. What I want to avoid is also powdering the gold--just flatten it some. Hey, what have you got to lose? Other than burning out the motor on the tumbler? :)

I'm a proponent of proven methods* but, with that said - If the tumbler does in fact shatter and reduce the non gold (maybe even free up gold that was attached or contained in them) without also further reducing gold size then, with proper screening and panning,etc., the results could be an overall positive. Time to put those new micro screens you bought to use.:thumbsup:

*I sometimes try to improve methods though and one of my improvements is the introduction of tube supplied water, in a zook, as if it was coming directly through the bottom of box. I have incorporated that in my homemade one. IMHO it has to be more efficient in the final sorting of the material in the box as it kind of replicates a lab type or commercial fluid bed system.
 

Last edited:
I'm a proponent of proven methods* but, with that said - If the tumbler does in fact shatter and reduce the non gold (maybe even free up gold that was attached or contained in them) without also further reducing gold size then, with proper screening and panning,etc., the results could be an overall positive. Time to put those new micro screens you bought to use.:thumbsup:

You know, I was thinking the same thing about those new screens. I now have 3 smaller sizes than the 100 Tyler Mesh screen that used to be my smallest. So, the +100 fraction, if put into a tumbler and works only to crush the gangue, then the gold might still be +100 but the rest goes through. I then check with the 112 mesh (120 micron) and take the + fraction and repeat; and again with the next two smaller screens.

The fact that it might only crush the other material in itself would be a positive! I had not thought of that. Thanks.


*I sometimes try to improve methods though and one of my improvements is the introduction of tube supplied water, in a zook, as if it was coming directly through the bottom of box. I have incorporated that in my homemade one. IMHO it has to be more efficient in the final sorting of the material in the box as it kind of replicates a lab type or commercial fluid bed system.
 

You know, I was thinking the same thing about those new screens. I now have 3 smaller sizes than the 100 Tyler Mesh screen that used to be my smallest. So, the +100 fraction, if put into a tumbler and works only to crush the gangue, then the gold might still be +100 but the rest goes through. I then check with the 112 mesh (120 micron) and take the + fraction and repeat; and again with the next two smaller screens.

The fact that it might only crush the other material in itself would be a positive! I had not thought of that. Thanks.

If the new screens nest/stack then all the better.

Have fun.
 

I saw another thread in another forum where a guy was going to use a treadmill motor to turn his rod mill. I have a treadmill and could fix a support system on it for the rock tumbler. Turn it on, let the belt turn the tumbler (put it inside a wool sock for better traction). Try for 7-8 minutes and see what occurs; I won't be even risking a tumbler motor.

I am also thinking of an iron insert for the tumbler (since the tumbler motor no longer has to be worry about total mass), though I will likely try the tumbler with the rubber lining first. I am looking for scrap steel/iron rods now. I don't want to use rebar because it is not smooth, so I am looking for another cheap source of rods. Any ideas are appreciated.

If the rock tumbler doesn't work, I will have to look at a steel pipe as my mill, though I saw elsewhere someone wanted to use a large PVC pipe. I am not sure that will work, but _if_ the rubber inside works for the tumbler, the PVC would certainly work. As an experimental chemist, I would say why not try it. You can always adjust after the results are in....
 

I saw another thread in another forum where a guy was going to use a treadmill motor to turn his rod mill. I have a treadmill and could fix a support system on it for the rock tumbler. Turn it on, let the belt turn the tumbler (put it inside a wool sock for better traction). Try for 7-8 minutes and see what occurs; I won't be even risking a tumbler motor.

I am also thinking of an iron insert for the tumbler (since the tumbler motor no longer has to be worry about total mass), though I will likely try the tumbler with the rubber lining first. I am looking for scrap steel/iron rods now. I don't want to use rebar because it is not smooth, so I am looking for another cheap source of rods. Any ideas are appreciated.

If the rock tumbler doesn't work, I will have to look at a steel pipe as my mill, though I saw elsewhere someone wanted to use a large PVC pipe. I am not sure that will work, but _if_ the rubber inside works for the tumbler, the PVC would certainly work. As an experimental chemist, I would say why not try it. You can always adjust after the results are in....


Rant on.....:BangHead:
I just don't understand why people seem to think that reinventing the wheel is so necessary especially reinventing the wheel with inferior components.
You are dealing with iron ores, quartz, as well as other hard elements and gold particles all of which will require HARD surfaces to accomplish the desired results.... CRUSHING & FRACTURING ore.

Not sure I would want to be around your lab during some of your experimental chem. projects.........
Rant off.....:dontknow:

Maybe you should use the signature line that Golly mr. science uses over on another forum ..... "Why don't we just keep adding stuff to this till it blows up or just smells really bad...."
 

Last edited:
If I tore up the treadmill for the motor, what would my wife use to hang clothes on?
 

Top Member Reactions

Users who are viewing this thread

Back
Top