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Small Scale Hardrock (Lode) Mining


Root

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Nice vid Trent. I didn't catch what you said the recovery rate was? Like how much gets past the bowl and caught in the sluice?

 

Also, what is that cap rock, is it like a cemented conglomerate type material? Or is that more like a quartz breccia type thing?

 

I'd definitely be interested to see some photos of contacts and vein systems or pockets themselves if anyone is willing to share!

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Ive found the recovery rate to be about 95% with that material, I dont even bother panning the material from the sluice any more as often there is nothing in it.

I did read a scientific report a few years ago that done a study on knudsen bowls and it showed recovery dropping off on basically invisible gold but I cant remember the %.

Yes, cap rock is similar to a cemented conglomerate, but formed differently. Conglomerate is usually deposited by water in rivers etc from material that has travelled. Where cap rock is more of a chemical weathering process of the bed rock below it.

Its common over here in Western Australia to get extremely rich patches in the cap from supergene enrichment of the reef below. The stuff Ive been processing usually averages 10-20oz per ton, but only get it in 1-2ton patches. Often it only continues a couple meters deep then you get a depleted zone where the gold has been leached out from.

Its a bit hot to go out and get pics at the moment, will have to wait till it cools down.

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I have found that recovery rate from the bowls are at 95% also. When I first used them in the recovey circuit I used two. One after the other,the second one didn't have enough gold in it to pay to run it.

Root

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:o   :blink:

 

Dude...that's amazing.

 

What mesh is the gold on average? Is there nuggety gold in that caprock stuff too"?

Yeh, there good grades but they dont come around everyday. I only found 2 with those grades in the last year. Most of rock I process is quartz reef which averages about 20g per ton.

Lots of nuggety gold in the cap, most of it can be detected. If you ever detect a nugget in the cap dig some of rock out from around it check it out, often you get more from that then the nugget ;)

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Has anyone tried any of the nonexplosive demolition agents like Dexpan? There are a few other alternatives. It sounds like dealing with powder is expensive here, wondering if they would be worth trying?

 

Or, I have a crazy idea. This wouldn't work in Arizona, but what about drilling your holes then filling them with water and epoxying a cap in place? When the water freezes it should expand and shatter the rock just like a nonexplosive agent should. Or at least that's my theory, if I get a good hammer drill I'm going to put it to test in a video. Rock would have to be nonporous and non fractured though, or filled in.

 

Hmm, actually in non porous/non fractured rock, what about just hydraulically fracking it with a cylinder pump pumping water? Just like the oilfield. I guess it'd only work for a real specifically small set of conditions though, especially on surface. Maybe interesting to try anyways if I get a good high pressure pump.

 

BD, I thought you might have been the author of that ICMJ article.

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Has anyone tried any of the nonexplosive demolition agents like Dexpan? There are a few other alternatives. It sounds like dealing with powder is expensive here, wondering if they would be worth trying?

 

Or, I have a crazy idea. This wouldn't work in Arizona, but what about drilling your holes then filling them with water and epoxying a cap in place? When the water freezes it should expand and shatter the rock just like a nonexplosive agent should. Or at least that's my theory, if I get a good hammer drill I'm going to put it to test in a video. Rock would have to be nonporous and non fractured though, or filled in.

 

Hmm, actually in non porous/non fractured rock, what about just hydraulically fracking it with a cylinder pump pumping water? Just like the oilfield. I guess it'd only work for a real specifically small set of conditions though, especially on surface. Maybe interesting to try anyways if I get a good high pressure pump.

 

BD, I thought you might have been the author of that ICMJ article.

I use expanda stuff, it works really well and its bloody hot here. I got a big drill bit on a electric drill. I get it from this bloke here in Australia, im sure someone over there would sell it too.

http://www.armstrongindustries.com.au/#!demolition-agent/c1vop

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