Question about concentrating micro-gold after pulverizing ore

[BentFunky]

What do you all do to concentrate micro-gold?

Concentrating gold after pulverizing rock to fine powder is quite a challenge.

Most of micro-gold gets washed away if panning or sluicing. Will try adding miners moss to sluice run but I'm not optimistic that this will be an adequate solution on its own.

Leaching isn't for me. Not willing to mess with cyanide. Gotta be another option, right?

 

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[arizau]

What do you all do to concentrate micro-gold?

Concentrating gold after pulverizing rock to fine powder is quite a challenge.

Most of micro-gold gets washed away if panning or sluicing. Will try adding miners moss to sluice run but I'm not optimistic that this will be an adequate solution on its own.

Leaching isn't for me. Not willing to mess with cyanide. Gotta be another option, right?

Assuming the gold you are dealing with is visible no matter it's size you can probably solve most of your problem by screen classifying your concentrates into batches of like sized material and panning each batch sepatately... gold is about 3 to 5 times heavier than other like sized particles so screening makes panning efforts fairly easy and much more productive. Many of us use 30, 50 and 100 mesh screens to create batches containing fine gold particles.

Good luck.

 

[Gambrinus]

If you are going to use a sluice box I would recommend using corduroy for the mat, it doesn't have a high recovery rate but it does work pretty well at a low cost.
You can buy it at most any fabric store and when it gets worn out you can just burn it and recover any remaining gold that won't wash out.

Here is a link that has info about using corduroy. https://www.911metallurgist.com/blog/cheap-sluice-mat

Another method is using a mercury plate but many people don't want go that route because of the hazards involved but it does have a high recovery rate.

 

[BentFunky]

If you are going to use a sluice box I would recommend using corduroy for the mat, it doesn't have a high recovery rate but it does work pretty well at a low cost.
You can buy it at most any fabric store and when it gets worn out you can just burn it and recover any remaining gold that won't wash out.

Here is a link that has info about using corduroy. https://www.911metallurgist.com/blog/cheap-sluice-mat

Another method is using a mercury plate but many people don't want go that route because of the hazards involved but it does have a high recovery rate.

@Gambrinus, appreciate the info. In particular, using something in place of miners moss that I can burn to recover gold is a really good idea. However, not a fan of using mercury.

Running finely crushed and classified material across a long run of collector material (e.g., corduroy) might concentrate gold enough. Easy enough experiment. Have a couple/few set-ups in mind that might work.

 

[Gambrinus]

@Gambrinus, appreciate the info. In particular, using something in place of miners moss that I can burn to recover gold is a really good idea. However, not a fan of using mercury.

Running finely crushed and classified material across a long run of collector material (e.g., corduroy) might concentrate gold enough. Easy enough experiment. Have a couple/few set-ups in mind that might work.

Did you go to the site that I linked? It has good information on how to set up a table. Corduroy has been in use for a long time and still gets used in fairly large small scale operations.

 

[BentFunky]

Did you go to the site that I linked? It has good information on how to set up a table. Corduroy has been in use for a long time and still gets used in fairly large small scale operations.

Took a quick look but will go back for details. Looks interesting!

 

[Mad Machinist]

Once gold hits about 250 mesh, it becomes very difficult to recover by gravity means. A little bit of Jet Dry in the water helps as it breaks the surface tension of the water.

Anything under 250 mesh is typically either flotation territory if it is a sulfide ore or leaching if it is an oxide ore.

A friend of mine built a cheap flotation cell from and old drill press and a big pot. I'll try and get a pic for you.

 

[Mad Machinist]

Here ya go.

 

[Mad Machinist]

https://www.911metallurgist.com/blog/homebase-flotation-tests-homemade-flotation-equipment

 

[Mad Machinist]

https://m.youtube.com/watch?v=N0GJgbSyYUg&t=15s