Hard rock mining. Crushing gold bearing rocks to 50 mesh.

Ace1mc

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Sep 7, 2020
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Las vegas
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I have been prospecting in several locations around one mountain. Have pulled about 200 lbs of gold bearing rocks out. I have crushed up 25% to 50 mesh and have run it through a blue bowl. But I see there is still gold going through. I have capured about 2 grams I believe so far.
I can not afford a shaker table at this time which would probably be better at catching all the gold.
I have found one nice small rock with. Signs of gold on both sides. I will post a picture here. The nice thing is there is no claims what so ever in the area that I am prospecting.
Anybody have any suggestions of being able to recover fine gold. I am not good at panning. I have about a 1/8 of a 5 gallon bucket of concentrates and probable another full 5 gallon bucket to break down to 50 mesh.
The blue bowl does not seem to catch a lot of the finer gold that I have.

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Jason in Enid

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Oct 10, 2009
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If you cant pan, you need practice. If your blue bowl isnt catching gold then either there is no gold or youre not using it properly. Not everything that sparkles in a rock is gold.
 

pczim

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Jan 4, 2015
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Mercury if it is legal where you are
 

Mad Machinist

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Aug 18, 2010
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Mercury if it is legal where you are

I'll be the one to speak out against using mercury, especially for a beginner. While it is very effective as recovering fine gold, it can also be a pain to deal with when it comes time to retort it. One good whiff of volatile mercury and it may be game over.

With the blue bowl set up to recirculate the water, i would try some Jet Dry and adjust the water flow. Your crushed ore will need to be screened by mesh size as much as possible. Start from the largest size and work towards the smallest while reducing water flow for the smaller sizes.

Dream Mat now makes a vortex mat for the blue bowl. I have not used it, but those that have say it works great.
 

Goodyguy

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Mar 10, 2007
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With the blue bowl set up to recirculate the water, i would try some Jet Dry and adjust the water flow. Your crushed ore will need to be screened by mesh size as much as possible. Start from the largest size and work towards the smallest while reducing water flow for the smaller sizes.

^ X2 ^ Best safest way to recover the -50 and finer, even down to -200 and smaller :icon_thumright:
Jet -dry is the key just dont use too much, a little goes a long way. If you see bubbles you used too much. Start with a few drops and only add a drop at a time from there if needed. There is no substitute for micro classifying, especially when running powdered rock.

The human eye can only see a single particle down to 50-60 microns (230 mesh) however when smaller particles -300 -400 mesh accumulate in the bowl they are readily seen.

Go for the Gold :3barsgold:
GG~
 
Last edited:

Mad Machinist

Silver Member
Aug 18, 2010
3,147
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Southeast Arizona
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^ X2 ^ Best safest way to recover the -50 and finer, even down to -200 and smaller :icon_thumright:
Jet -dry is the key just dont use too much, a little goes a long way. If you see bubbles you used too much. Start with a few drops and only add a drop at a time from there if needed. There is no substitute for micro classifying, especially when running powdered rock.

The human eye can only see a single particle down to 50-60 microns (230 mesh) however when smaller particles -300 -400 mesh accumulate in the bowl they are readily seen.

Go for the Gold :3barsgold:
GG~

Wish I could see down to 230 mesh again. Damn eyesight is going. Getting old.sucks rocks. Gonna need bifocals soon. Lol!!!!
 

utahvikingr

Jr. Member
Nov 3, 2020
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Make a shaker table, and you’ll be able to get micron gold ;) well, 85% or so of 50micron. A human hair is 90 micron, so you do that math.
 

CGC Miner

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Nov 18, 2010
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Blue bowl with straight crushed rock would be a nightmare. You have to feed so slow that it is not practical in my opinion. Also, freshly liberated gold from rock is typically really angular, flat, scaly, thin etc. and small which makes it very difficult to pan and process via high flow gravity techniques.

A better bet would be to crush your rock, wet it, jet dry and then feed through a cube and or fine gold recovery sluice. Run it twice. Pan those cons or try them in the blue bowl.

I imagine this would be much much faster and give you higher recovery rates.
 

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