Black sands

[Anonymous]

It seems that i get more black sands than i do gold when prospecting , Ive heard that they can be processed to remove very fine gold, how do i go about doing this? And does it make a difference between the magnetic black sands and the non-magnetic?

 

[jerrycranium]

It does make a difference, you can search for geological reports in your area about what the sands contain. You should seperate, crush each and test to determine what is where.

I get pounds and pounds every day gold dredging, its something that is unavoidable. In order to retain the majority of the fine gold you have to collect some black sand too. I adjust my sluice to where its performing best. Should have about an inch space between the sand behind one riffle to the next riffle.

 

[ChucknC]

Here's a simple method to help seperate black sands from fine gold.
Simply mix an equal amount of Uniodized salt with the cons and heat it to scorching. This will almost be up to a red heat on a piece of iron. Pour the heated Cons/salt mixture into a bucket of ice water. This will fracture the black sands releasing fine gold, as well as the salt corroding any "creek varnish" off the gold.

Another thing you can try is to add a small amount of Wick's Rust and Iron Remover to a plastic container containing black sands. There is some highly dilute and buffered HF in this product, so use all safety tips listed on the container. Wick's can be found in the cleaning aisle at Wal-Mart.
Rinse with water and nuetralize the liquid with baking soda.

After either method, you'd be shocked at how much fine and finer gold is released. Oh, seperate the gold from the remaining black sands by your favorite method, panning, blue or green bowl, gold wheel,etc.

Chuck

 

[jerrycranium]

Thanks Chuck, will try it out.

 

[blueduck]

Some of the "blacks" and "browns" in Central Idaho are tellurides which when heated release gold, some have sulfides covering them and that too has to be removed before acids will touch the gold and put it into solution.

If you screen out the material to a very fine mesh and put it on a shaker table for specific gravity you will find the various weights of blacks and some of them are heavy.... like 3 inches in the bottom of a five gallon bucket will be enough to keep the bucket on the ground and the rip the handle off of it... some of the blacks are actually "green" in color and contain the mineral used to put the solid rocket boosters full of fuel and send the shuttle into space.... there is more to black sand than magnetic sand in those concentrates.... and some of it is very valuable..... but not all places have such mineral deposits all around the world

If when you heat your "blacks" you get a rotten egg smell you are burning off sulfides, and that is a good indication there is "gold in them thar sands" and acids can be used to put it into solution.

William
Central Idaho

 

[Flashman]

Heh, I got excited reading this when I remembered a lake beach that had a lot of black sand on it... then remembered it also has freshwater mussel beds.

 

[JOE S (INDY)]

Black Sands, in the areas of North America that I am familiar with, are usually comprised of Magnetite Fe2+Fe3+2O4 and Hematite Fe2O3. Both minerals are dense enough to irritatingly interfere with gold recovery from the densest stream concentrates.

To further complicate matters there have been various persistant claims that substancial micro-gold values have become ‘locked up’ in the sands, defying gravity separation.

A few small scale miners have expressed a wish to fire their densest black sand / gold concentrates. They are anticipating the use of a flux in order to melt, separate, possibly smelt and eventually recover the micro gold. The crux of the problem is the lack of information as to what will work.

So, is there an ordinary and established way to recover gold from highly concentrated black sands? Is there, in fact, a flux which is customarily used here? I'm just looking for general information - not any "Double Secret" stuff.

Thanks!

Joe

 

[Froggy]

Joe, Good to see you . I read alot of your post on the Alaska forum. I'm surprised Blacksandsman doesnt know this answer. But the guys here are really guru's... good luck, frog

 

[blueduck]

.....
So, is there an ordinary and established way to recover gold from highly concentrated black sands? Is there, in fact, a flux which is customarily used here? I'm just looking for general information - not any "Double Secret" stuff.

Thanks!

Joe

What does your blacks do when subjected to a shaker table? here in central idaho, the folks that use the tables on the screened material get really good separation into the various specific gravities enough to make a large table worth their efforts, they still loose the "flat" or 2 sided gold [if you have not seen this its hard to explain, cause it does not like to lay down in a sluice but you can see it and if you can "fire" it you can acid it, but generally it floats away whilst the heavier particles remain, though it is not always microscopic, using a loup makes it easier to see]

AN old miner who passed on last year told me he used hydrofluoric acid on some of it, but until the sands touched a 800 degre flame/heat the acid would not touch it..... and there is gold in those backs around here.

William
Central idaho

 

[OMG]

I'm working on a way to dissolve and plate the iron out of the concentrates. That way if there is any gold locked up with the iron, then it will be released for sure. Things look good. The electrolyte does not get used up, and I have had some success in tests so far.
Right now I'm working on getting an actual system setup instead of some jury rigged thing. I'll keep posting my results.
My idea is to remove the iron and other lower metals out of the concentrate, then dissolve the pgms using the HCl-Cl method right afterwards, leaving just silicates and whatever else doesn't dissolve in the bottom of the cell.

 

[mikeore]

I'm going to the same place, I'm just going around the other side of the house.

 

[goldsilverpro]

OMG,

I hope that you've proven a small, jury-rigged setup before you went to a production setup. You don't want to get locked into a process that doesn't work.

 

[JOE S (INDY)]

Hey there William,

Lets see now - I have seen a shaker table, -- , but then again, I have also seen Air Force One. Neither of them are probably within my reach in this lifetime. The particle size which seems to be of primary interest to me, and many other miners though, is the sub-visible gold.

While leaching, recovery and melting would work, most dirt miners are a bit gun shy on any more chemical activity than, say, Sodium Chloride on their eggs in the morning :lol: . (ok - really over stated, I guess - 'specially since I'm a dirt miner too. )

As far as portability goes, a muffle furnace, a little flux, a propane bottle and a little compressed air is preferable to Wee Small Scale Miners (all puns intended). While larger operations are able to handle the micro gold in black sand (either with equipment or by indifference to lost values) we little guys can't. Our choices are Mercury (OK, Here comes Irons!!!), or Leaching (time and physical facilities, not to mention endless forms, permits and inspectors) or small operation melting/smelting.

For the most part we're not talking about bunches of material to run. Careful concentrating of values could work down to just a few kilos of super concentrates a week (or month) for most very small miners. Good Rainy Day Work.

So, if there is a recognized simple way to work down a half litre batch of the very heaviest material, using can't-go-wrong primative equipment and a simple "Cookie Recipie" flux I'd sure like to learn it.

I'd much rather not have to worry about Mercury (Look at Irons grin!) while still recovering the 'tiny gold'. I'm sure that many other miners feel the same way, too.

Thanks again, all -- Really an awsome site you have here KNOXX!

***
Oh, on the Hydrofloric Acid, Really Nasty 'Stuff'! I prefer to leave the glass eating acids to others.
***

Joe

 

[Noxx]

Thanks Joe !

And we don't really use HF either... :lol:

 

[markqf1]

Hi Joe,
Check out the forum on www.weekendgoldminers.com.
There is quite alot of info on black sands, magnatite and hematite,
house flux, and smelting fine gold. It's also a great club to which I belong here in Ga. I hope it helps.
Mark

 

[macfixer01]

If you screen out the material to a very fine mesh and put it on a shaker table for specific gravity you will find the various weights of blacks and some of them are heavy.... like 3 inches in the bottom of a five gallon bucket will be enough to keep the bucket on the ground and the rip the handle off of it... some of the blacks are actually "green" in color and contain the mineral used to put the solid rocket boosters full of fuel and send the shuttle into space.... there is more to black sand than magnetic sand in those concentrates.... and some of it is very valuable..... but not all places have such mineral deposits all around the world

William
Central Idaho

I don't know what "mineral" you're alluding to here, some aluminum compound? As far as I know the space shuttle solid rocket boosters are made from mostly Ammonium Perchlorate and Powdered Aluminum, with Carbon Black added for optical opacity to prevent formation of hot spots, and some variety of Polybutadiene resin as a plasticizer.

macfixer01

 

[JOE S (INDY)]

Thank you, Mark!

I'll certainly do that.

Joe

 

[blueduck]

.......

I don't know what "mineral" you're alluding to here, some aluminum compound? .......
macfixer01

I dont know either, the miner that told me of what was being taken out as he watch passed away last august from diabetes related causes coupled with his having been exposed to agent Orange in the national forest here in Central Idaho back in the 1970's..... he was also the fela that used Hydrofluoric acid in a limited degree with his cyanding and nitric use..... his dad was a propector in the Downieville California area in the depression and he continued the trade for the most part..... the knowledge of folks like him is lost forever except to that of which was imparted in people like myself that can be faintly remembered, and faintly is about all I can remember of some of our conversations some of which lasted 18 hours at times when i could visit with him.... waiting for the still to finish out..... he had many talents, at least i remember the recipe for making alcohol to run a vehicle on.

Lets see now - I have seen a shaker table

solution is to make your own if you cant afford to purchase one, though Action Mining M4 is nearly affordable being $2400 and 175 pounds, made for sampling, it will run 50 pounds per hour, which if you recover enough that you are missing currently, then it pays for itself, and then it pays for a larger model.

Leaching (time and physical facilities, not to mention endless forms, permits and inspectors) or small operation melting/smelting

Though i am not a sales person for them and maybe sound like it, but i dont get anything out of it, action mining has some small scale systems for leaching that might work for your smaller scale operation [shoot if there are others outfits around that want me to take a look at what they have and be a promotion mouthpiece for them i am willing to take a look] , and maybe not even need a permission slip from any subservient governing body..... the only way someone can tell you no you cannot do that is to ask in the first place, for then you consent to voluntary jurisdiction over your project from that point on..... but since i am not an attorney i am not giving legal advice, and in no way should such be construed as such nor should you hold the author nor the website and its owner or owners responsible for anything you might garner from such written words without forst consulting the proper research facilities and a "trustworthy" [if you can find one] professional attorney...... <----- maybe i ought to start putting that in my signature line eh?

And we don't really use HF either...

I did not advocate the use of it, though if you read Chapter 16, Some More Special Cases at page 182 in CM Hokes book, you see even she made it clear that in some instances the use of Hydrofluoric is warranted to get rid of "sand, glass, porcelain, and enamel". Though i suspect with current regulations what they have become, getting the acid in any quantity is not easy, to many people having too little common sense, and feeding others fears of terrorism that does not as of yet exist. I do think there is a better way to dispose of a chemical acid than just pouring it down the drain as she proposed in her writings.....

William
Central Idaho

 

[blueduck]

here is a shaker table to download, its not plans but if a person was creative they could build one very similar just off the pictures and description alone.

Page 42, 46, 47 show it, the rest is pretty much reading..... though i spect those who like reading and looking at the other pictures will find it interesting as well.

shaker table in pdf format 5.21 megs on disk if the link dont work i have it on my hard drive and will upload it here.

found the document at

http://www.bgs.ac.uk/dfid-kar-geoscience/database/reportlist.html and it is also there in a band white version of only 2 megs..... but I like the color version.

William

 

[macfixer01]

.......

I don't know what "mineral" you're alluding to here, some aluminum compound? .......
macfixer01

I dont know either, the miner that told me of what was being taken out as he watch passed away last august from diabetes related causes coupled with his having been exposed to agent Orange in the national forest here in Central Idaho back in the 1970's..... he was also the fela that used Hydrofluoric acid in a limited degree with his cyanding and nitric use..... his dad was a propector in the Downieville California area in the depression and he continued the trade for the most part..... the knowledge of folks like him is lost forever except to that of which was imparted in people like myself that can be faintly remembered, and faintly is about all I can remember of some of our conversations some of which lasted 18 hours at times when i could visit with him.... waiting for the still to finish out..... he had many talents, at least i remember the recipe for making alcohol to run a vehicle on.

William
Central Idaho

Hi william,
Thanks for your reply, your original post had piqued my curiousity. I believe the high power rocketry people use some copper and maybe chromium compounds for catalysts also to speed up the burn rate. That might fit with a greenish mineral.

All the best,
macfixer01