# Quest to get Au from sand and let some shmuck buy [email protected]$800/oz



## OMG

So this has been my experience so far:

I've gone out to the wilderness to collect sand from creeks. I have about 2 gallons of about 1mm sized sand and black sand and gold and whatever_else_happened_to_be_there mix

I tried using mercury in my gold pan with some black sand concentrates that had very fine gold in them to see what would happen.

Results: It does pick up gold, but not too efficiently, i would roll the mercury right over a piece of gold and it might not pick it up the first time, so i'd have to run over it a few times. And I couldn't get it to pick up any of the really tiny stuff - I think the plastic of the pan's surface was irregular enough to hide the tiny flecks from the mercury. And another problem - the mercury would break apart and even tiny fleck/balls of mercury would get lost in the pan.

My other Test: I took about a 1/4 cup of concentrates and put it in HCl for a few hours, then rinsed it out and did that again. (I dissolved pretty much all the black sand as well as cleaned up all the other sand too)

Results: What I ended up with was a sand mix with waay more gold than I thought was in there and a whole bunch of shiny silvery flakes that I never saw before (I'm hoping they are platinum . So I brought out my mercury again and started rolling it in the pan of clean stuff, and it still didn't pick up gold right away, but it seemed to pick up something because within a couple min of rolling around it lost its shininess and turned to a solid light grey color. I was clumsy and a piece of the mercury broke off the main ball. The piece that broke off was not acting like mercury at all. It was a little string shaped thing that didn't want to move much. Eventually it turned to a little ball, and I rolled both balls out of the pan.

So now my next adventure will be getting/making a retort and retorting the mercury to see how much stuff it held, and then figuring out the best way to separate those metals that are left.

I am still researching for a good way to get all of the gold out of the sand.
I'm sure it will involve dissolving the gold, but I'm not sure the best and least expensive way to do it.

Any comments or knowledge anyone would like to share that will help me on my quest would be great.


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## Noxx

Please don't use mercury...

You can easily use AR on your concentrates to dissolve PMs


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## OMG

I'm careful with mercury. The reason I like it is because it is recoverable. AR is too expensive for the volume of material I need to process.
But in any case, I won't be using mercury much, I was just trying it out.
I'm thinking need to use some kind of leach. I'm looking at chlorine leaching for the first phase of processing - removing the iron. I'm trying to figure out if I can electrolytically generate chlorine compounds that will dissolve the iron, and then use the NaOH produced in the reaction to precipitate it back out later on. (essentially having no input costs except electricity)

BTW, does anyone know what metals perchloric acid will dissolve, or had any experience with it?


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## Irons

It takes just a minute quantity to destroy the nervous system of an unborn child. Just a couple of grams can make the fish fom a large lake of several square miles unfit to eat.

There is no such thing as a safe level of Mercury.


The few dollars you might save might cost the State where you live Millions to restore the land where you dump your waste.

If you can't recover your values safely, you sould find some other way to entetain yourself.

Don't be a peckerwood.


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## OMG

LOL. No one has called me peckerwood in a long time.
Ya, mercury isn't safe to eat, but one good thing is that if you use it right it produces no waste.


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## DeadDOG

*If mercury is naturally occurring, why is it a problem? *
In nature, mercury tends to be bound up in rocks and soil, widely dispersed, and does not easily enter the food chain. But when humans extract mercury from rocks for various purposes, or burn fossil fuels, it is released into the air and water, where it can enter the food chain more easily and become concentrated in ways that would not typically occur in nature.


*What is mercury and where does it come from? *
Mercury is a naturally occurring metal that can be found *at very low levels almost everywhere.* Many people are familiar with the silvery liquid form of mercury found in thermometers.


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## Steppegold

"Ya, mercury isn't safe to eat, but one good thing is that if you use it right it produces no waste." Sorry folks, that is not true, using mercury always produces waste. And not only solid waste. The other day we checked how much Hg was in the air in our office, next to zero. Then we took the lid of a small jar of Hg-contaminated tailings, and the level of mercury reading shot up by 10,000-fold. We evacuated the room.


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## Anonymous

Retorting... Research the technique VERY thoroughly. If not done correctly, you will either expose yourself to extremely toxic mercury fumes, and or blow up the retort, and possibly yourself.... or parts thereof!
NEVER EVER submerse the recovery tube under water. When the retort cools, the resulting vacuum will suck water into the retort and cause it to explode. If you must retort, I suggest making a 'tube' of some denim from old jeans. 2 layers thick maximum. Attach one end to the retort, let the other end sit under water. The denim is porous enough to break the siphoning action of a cooling retort, yet solid enough to condense most of the mercury vapour passing through it. It works very well as I have used it on my own retort. Do this procedure well away from anyone, or anything that could be damaged by fumes or explosion. I didn't hang around when my retort was working, just in case. Now it sits, in a box, in the corner of the shed sealed in plastic. If you really want to extract maximum value from your sands, it will have to be smelting, or leaching. For acid leaching you will need to buy a decent PH meter and an ORPmeter, to accutately keep the PH low, and the ORP below 900, or the waste metals will eat your leach faster than you can replace it leaving you with gallons of liquid waste at a substantial cost. Never mind the danger of mixing the wrong chemicals and producing deadly gasses.... like hydrocyanic gas (what they use in gas chambers). If you leach, start very small until you are sure of your procedure.


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## OMG

Ya I am thinking of using some kind of leach. What is ORP? And what is a good type of PH tester?

I've been looking up electrolysis and electroplating.. looking for some way to dissolve the iron from the sand then plate it from the solution but I haven't had much success. I guess plating iron is probably not used much.

Does anyone know if there is maybe a way to use an electrolytic solution that will dissolve iron and be able to plate it back onto one of the electrodes?
Like making a (HCL + ?) electrolyte and having it dissolve the iron particles in the sand and then plate it back out from the solution immediately?
(could that be possible to keep something plating while the solution is trying to dissolve what your plating?)
If anyone knows anything that would shed some light on any of this or can point me in the right direction...
many thanks


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## Smitty

Hey OMG, how are you able to dissolve the black sand in a few hours when I'm still trying to dissolve my own black sand for days now? Of course, I'm using HCl and Peroxide which is technically stronger than just HCl alone. Maybe I'm doing something wrong? Read the thread about separating Pyrite from Gold thread for my results, maybe you might find something I'm doing wrong.


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## OMG

I had about a quarter cup of sand, and like yours the HCl turned pee yellow right away. When I was finished and swirled the sand around in the pan, I now know that the little shiny flakes (that i was hoping were platinum :? ) were actually pyrites. There was probably about 5x more than was visible before the HCl, so I doubt that any were dissolved. I'm not sure why my black sands dissolved a lot quicker that yours seemed to.
I tried another batch (a bit bigger) since then and left it for days, and the yellow solution got very very intensely yellow. Like liquid yellow dye (almost orange looking).
I'm wondering if maybe your HCl is being used up dissolving other things in your sand that my sand didn't have.

Right now I'm trying to research a more efficient way to remove the iron. Something like setting up an electrolytic cell (using a chloride salt electrolyte and breaking it) to generate chlorine at the anode to dissolve the iron. (I want to get a titanium plated 'disc' as the anode and put a magnet under it so the black sands will be magnetically attracted and be in contact with the anode - forming iron chloride right there, and eliminating some of the escape of the chlorine gas, and speeding up the dissolving of them). I think that should work ok since the iron is magnetic and it conducts electricity.
Now I'm trying to find a suitable chloride salt. I'd like to be able to plate the iron right onto the cathode.


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## OMG

I think I may have just found a good way to remove the iron from black sand concentrates. Using electrolysis you essentially reduce the particle size of the iron so small that it will stay suspended in water for hours. Being so small, you could pour it off without pouring off the sand concentrates in the bottom.
Here's my idea:
- crush the black sand so its all very small (no so small that it stays suspended in water for long, but pretty small)
- make a electrolytic cell with just saltwater and the black sand concentrates
- the anode will be a titanium (plated) flat disc or sheet (it's titanium so the chlorine produced there wont eat away at it), and you put a strong magnet underneath the cell so the black sand will get pulled toward the disc and stick to the titanium. You should then be able to just stir up your black sand and the iron will stick to the plate before any other stuff settles down on top of it.
- when you apply current, the cathode will generate chlorine, and since its generating the chlorine right on top of the iron, FeCl3 will form.
- at the cathode, the sodium from the salt is making NaOH and hydrogen gas.
- you don't actually see the NaOH being produced because it immediately reacts with the FeCl3 being produced and precipitates the Iron (as FeO I believe).
*But the catch is that the FeO is very very very small and will stay suspended in the water (and it is not magnetic btw - not sure why, maybe the size of the particles).
So after a while, you should have a container of black liquid, which you let the bigger particles settle for a few seconds and pour off all the fine FeO particles, and you'll end up with more concentrated concentrates!

I did an experiment before that if I would have thought about it I would have come up with this sooner.
I just did normal electrolysis of saltwater and tried using an iron anode. The reaction was quite quick and I saw iron particles pouring off the anode. The water turned black quickly, but I let it run for a few minutes before I stopped it. The cell has sat for days now and the iron oxide particles have settled. I stuck a neodymium magnet in the black (FeO) goo to see if it was magnetic and it wasn't.

So now I'll try to set up the cell properly with a titanium disc and a magnet to see how well it works, and I'll post my results. (I'm a little concerned about how slow it might be, but we'll see)


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## mikeore

I think you are on the right track with an electrolic cell.
Good old black sand. During dredging season we get overwelmed with it.
How we handle it is to high grade the bigger gold off, store the dredge cons. We will then table it when we have the time (small in-water work window) This will get just about all the gold you can possibly catch by gravity.
What you are dealing with is Hematite and Magnetite (iron) Magnetite is easy to deal with, it is magnetic. Just get a magnet and pull it out. Hematite, not so easy (except with a table) Not all black sands have Au. and Pt. It is"on" it not "in" it (although Ma nature is always full of suprises) You have to exam it under a microscope. Some people fry in salt in a pan and throw it water to thermaly "shock" it then pan(it works)
The name of the game is concentration, get rid of as much junk as you can. For smaller quanities we do this:
Take your cons and mix them with Lead wool or powdered Lead, and a little Borax. Put it into crucible and into the furnace and melt. What you are doing is making Lithage. This is the Aqua Regia of all things molten. The Lead oxidizes into Lithage, witch happens to destroy all minerals except precious metals.
Take it out, when it cools pound all the slag and crud off. pound it into a cube. Get a cupell( A"crucible" made out of bone ash or Magnasite)
Back in the furnace with ya. What happens is the cupell absorbs the Lead and leaves the "good Stuff" gold, silver,Pgm's as a bead.
Next step is called parting. Take your bead and out put it into Nitric acid, this puts the silver into solution leaving the goodies.
I'm talkin' as a miner here not a refiner. We have to produce product to keep our operation going, it's pure enough to sell at a good price. Fuel,fuel,fuel oh yeah beer.
I have experimented with leaching black sand with good results, but I don't think the return's is worth it. It was a commercialy purchased leach that was compatible with electroics, but just never got to that point. 
Of course I'm gonna throw in that this whole rant is just my opinion. And if you guy's are beyond this process I'm sure you will let me know.


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## OMG

I've never heard about Lithage yet. Sounds interesting. I'll have to read up about it. What does it cost to get a furnace up and running able to melt metals like this? Sooner or later I'll have to get a torch, furnace, and whatnot so maybe I'll get it sooner. What kind of fuel do you use? (er. I mean what kind of fuel does the furnace use). Does it cost very much in fuel (and other consumables) to process - say a gallon of concentrates?


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## mikeore

Hey how are ya? This an old assay technique. It has been has been around for 2000yrs. or so. ( so I can't claim invention)
A good electric furnce (9x10x6.5) can be had for less than $1000. If you keep your eye's pealed you could pick one up used. You have to get a tempreture rating of 2300F continuos operating temp. It's pretty standard mining and milling equipment. Or I suppose you can build one yourself and use propane. Clay crucibles run about $3.00 or so. Bone ash cupell's run about $1.30 ea. but they are a one shot deal so you buy 20 to a box ($1.00 ea.) Related equip. crucible tongs, gloves stuff like that. It adds up but if you set a goal and get a little bit at a time you will be there before ya know it. It is definitely fun stuff.
Also this is done outside, nasty fumes with this biz. You can and will get hurt if you don't take care. No such thing as a minor accident with molten metal and Lead fumes.
I can look around for some links I have somewhere an dsend you an e-mail.
Your not going to get alot of gold out of black sand but you will get alot of experience.


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## mikeore

[IMG:600:449]http://i241.photobucket.com/albums/ff124/fireman1_bucket/DSCN0959.jpg[/img]

[IMG:500:375]http://i241.photobucket.com/albums/ff124/fireman1_bucket/zzzzzzzzzz.jpg[/img]

[IMG:320:240]http://i241.photobucket.com/albums/ff124/fireman1_bucket/document.jpg[/img]
This is alot better than Black sand!!


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## lazersteve

Mike,

Welcome to the forum,

Nice native gold nuggets. It makes me wonder how much micron sized gold is in the same dirt.

What's the minimum sized gold particle that your process will capture?

Do you reprocess the heap after getting out the larger nuggets?

Any ideas on the purity of the native nuggets?

I've always wanted to do some real prospecting one day, looks reallly fun.

Keep up the great posts!

Steve


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## mikeore

Thanks, There is fair amount in the dirt but your talking mass earth moving/processing. I have tested it, it's in there. I was toying with the idea for a few years of filtering the water in the winter. On one of our claim's it is at the end of a very rich mineral belt. By the time the gold has traveled down ,it is ground up super fine. It is actualy fine enough to float from surface tension. My pardners think I'm crazy but I want to get a filtering system up and see what comes out. Mabey this winter :twisted: 
There ain't much left after we get thru mining. We are brutely efficient (well, most of the time anyways)
I'm on the Rogue River in S.O. Oregon. Our gold runs an average of about 995. average. It is known for it's "clean" gold, very purty. Some Pt. occurence (always looking) 
That red dirt (latrite soil) in the picture is Tertiary river bed, notice the round river rock's? It averages around 1250' above the present river. Old stuff. And it's loaded with color. I'll post another picture of it down to the bed rock.
As far as cupelling, like I said it is mostly an assay tool so I don't think it would be practical for production. But for a small footprint operation it would work great. A 2.25" Magnesite cupell will absorb 150g of lead. so that's a fair amount of gold. There are other ways to skin a cat.
Oh by the way miner's deal in dwt. oz. and pound's (troy) so if I get screwed up with weight's and measures on the forum ....well that's why.
I noticed another Guy that joined the forum that I know from another site. Steepe gold, he is in Mongolia mining. They are having a gold rush there right now. He has some awesome pictures. Have to start buggin him to post.


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## mikeore

[IMG:700:525]http://i241.photobucket.com/albums/ff124/fireman1_bucket/4.jpg[/img]

Mixed with overburden

[IMG:750:562]http://i241.photobucket.com/albums/ff124/fireman1_bucket/416051.jpg[/img]

This is what The "old channel" riverbed look's like. Notice how the rock's are rounded from rolling down the river. They realy get backed in there. 
The old timers pulled million's of dollars out of this type of material.
Oh yeah Lazer, if you ever make it out to the Left coast we'll take ya out.


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## Irons

"t is actualy fine enough to float from surface tension. My pardners think I'm crazy but I want to get a filtering system up and see what comes out. Mabey this winter"

Have you tried to add something to the feed to break surface tension so the Gold won't float?


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## mikeore

Hey Irons, I know what your getting at. Let me try to explain better.
This creek (river?) when it is running hard it is about 50yds. wide and going about 20mph+ (?) fast! It churns all that silt and fine gold up. The gold then floats. You have to look at it at the right angle with the right light. You can't realy drop it in situ.
My thought was to get an old swimming pool filter system/parts/cheap and try to capture some of the flow. It would be a coup just to get an intake system to stay in place without getting swept away. What would be cool is to design it so it is gravity fed. That way you could set it up and go do something else, come back and get whatever was in the system.
Kinda like a bank account. Don't know if it is practical or not.


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## Irons

The Gold tends to be very fine and will float on the surface of the water with the least provocation. Even a greasy fingerprint in the pan can cause the fines to float away.

Why not make a floating trap that collects just the surface water and catch the fines in a trap as they float off the back of the dredge.

I must admit that a 20 mph current will cause a lot of drag, though.


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## Irons

Irons said:


> The Gold tends to be very fine and will float on the surface of the water with the least provocation. Even a greasy fingerprint in the pan can cause the fines to float away.
> 
> Why not make a floating trap that collects just the surface water and catch the fines in a trap as they float off the back of the dredge.
> 
> I must admit that a 20 mph current will cause a lot of drag, though.



Another idea would be to attach a plate to the outlet of the dredge that skims the top quarter inch or so of the outlet water and directs it to a fine mesh to to filter out any solids that might float off. It would make a great bark catcher. :smile:

On edit:

Skimming the whole stream might be a chore, though. All it would take is a floating snag to sweep everything away.

I like the Idea. I had been thinking of trying something similar myself.


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## mikeore

Our window for in-water work is in the summer. The creek is way slowed downed. If you were to jump in it at high flow you would probably never be seen again. Skimming is defintely not practical.
Our dredges put out 400gpm and 15yph(yards per hour) so hanging something off the back would not work. We make BIG holes. The box tender can walk around on top with an ice chest. Large equip.
Most of the gold we recover is in the top part of the box (if it starts showing up after the 4th or so riffle you have to readjust somethings. We get real good fine recovery.
I'm afraid my idea is a winter project.


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## Irons

I wait until Summer as well but a friend of mine had this idea of going out during Spring fllood to beat everyone else to the new material. I suggested he wear a life preserver in case he fell in.

Monday he didn't show up for work. I found out he was recovering from hyperthermia from falling in. He told me that he originally laughed off my idea but decided to wear a flotation vest. He was glad he did. It took about 30 seconds before his extremities started shutting down in that near freezing water. Luckily, he was able to grab a tree root and pull himself to shore.

He was one miserable puppy. No matches to light a fire and all his clothes were soaking wet. He was lucky he didn't freeze to death.


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## mikeore

Hypothermia is the biggest killer out here in the winter, if your wet and can't get dry and warm you...are...dead. Sneaky killer. We can' t dredge in the winter due to Salmon runs. But you go across the border (CA.) you can work the Klamath year round. Too cold for this ol'boy. The Klamaths' water goes up and down, fast. I have had friends loose all their equipment overnight. 
I'll just stick to digg'n dirt in the winter thank you. At least you can have a fire!


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## blueduck

OMG said:


> So this has been my experience so far:
> .....
> I tried using mercury in my gold pan......
> 
> Results: It does pick up gold, but not too efficiently, i would roll the mercury right over a piece of gold and it might not pick it up the first time, so i'd have to run over it a few times. And I couldn't get it to pick up any of the really tiny stuff - I think the plastic of the pan's surface was irregular enough to hide the tiny flecks from the mercury. And another problem - the mercury would break apart and even tiny fleck/balls of mercury would get lost in the pan.



Mercury will attract the tiniest particle so free gold *[as long as it holds the proper charge],* it will however pass over anything that is attached to the gold in amalgam or which is separating the surface from the two contacting ergo passing over the gold, and the mercury will only pick up a set amount and when it is full that is it and you nee to clean it via one of several methods.



OMG said:


> ..... and a whole bunch of shiny silvery flakes that I never saw before (I'm hoping they are platinum.....



Here in Central Idaho, I found a substance I thought might be Pt, because it layed down in a pan easy and similar to the gold that was there, but it also could be a rare earth like a Monazite as we have deposits that have such in the area.... I have not taken the small amount i had to anyone that might be able to show me what i am looking at yet, nor have I followed the creek up to see if I can find the source where it comes in at either.... but I have a pretty good idea. I found a book titled National Audubon Society Guide to North American rocks and Minerals [available from Miners in Riggins Idaho along with a few better books but I found mine at a yard sale for a dollar and did not have to pay $20] the book has a lot of information and nice pictures in color, in addition a person needs a good looup or better yet a microscope to see the magnification properly to make certain determinations. American Science & Surplus has some really nice scopes for just about any budget currently, as well as glassware for some testing too.



OMG said:


> So now my next adventure will be getting/making a retort and retorting the mercury to see how much stuff it held, and then figuring out the best way to separate those metals that are left.



Instead of a retort, look at the products Action Mining in Oregon has to recover your mercury, for small amounts the syringe and cotton ball method works for filtration, and then they have a nice big unit for getting the mercury to recharge. The old timers used potatoes and a teaspoon to get their mercury off the gold, they would heat it up and the mercury would go up into the potatoe and the gold would be on the spoon, then as it cooled down the mercury would come out of the potato and be charged ready to work again, this however is some of what caused mercury poisoning amongst the miners and such a method should be avoided lest they be playing the funeral dirge for ya soon.... then anything goes as health issues would be the last of yer worries eh.




OMG said:


> I am still researching for a good way to get all of the gold out of the sand.
> I'm sure it will involve dissolving the gold, but I'm not sure the best and least expensive way to do it......



Using a shaker table is about the best way to ultimately separate your concentrates due to the specific gravity, however getting the concentrates to uniformity is the trick, and getting a shaker table that is the correct size for your volume without a huge investment is near impossible, but action mining has some tables that are not completely out of the zone, still an operation of any size requires real estate to set up on, and power, and water, and be able to clean up reasonably inexpensively [peddling the different separations is the key to making a table work for you and not you work to pay the table expense] NO matter how a person sets up they trade off being able to volume of concentrates for the loss of percentage of end product, or if they recover 99% of what is there then the trade off is in that the ability to run massive amounts of product through go away until they get into really big dollar investments.... small scale is a really hard thing to accomplish in any endeavor that you get everything you desire, something has to give somewhere and then you can go back and work on the scaling up or reducing the loss in the first attempt to recover. As a side note I have witnessed a fella take his 2 inch dredge in behind a 4inch and pick up a half ounce of gold in thier tailings that they did not think they were loosing [the 4 inch re-ran to make sure they were set up and still lost gold] just because they could run more material and recover alot more free placer gold did not mean the machine was catching it all as my friend showed them, the problem with the 2 inch is that he cannot move very much material in a day in most creeks around here for all the hand moving of the larger rocks, but in all at the end of the season he gets about what he needs to stay mining and cover his expenses and then some.

When you start using acids to remove the sand from your concentrates you probably will find it is way to expensive to even try, many have tried before and even the big outfits that heap leach sort there ore bodies to get the better ore in the right heap..... I guess if it was easy everyone would be doing it and then there would not have been a need for this forum, so since it is not as easy as it seems, there is wealth of information here that can keep some folks from re-inventing the wheel in the wrong manner and at the same time spark some one into a new direction that may, after the past 2000 years of folks trying, be a way that allows for easier recovery so dont let me discourage your thought process..... 

Lord knows the fellas on here slowed me way down and made me read a lot of things to catch up on before i made mistakes and by doing so have helped me keep my process in a realm that is doable!! which is a great thing btw. And hopefully other folks will also learn a little before doing too.

Have an EXTRAORDINARY day! :-Þ 

William 
Central Idaho


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## skyline27

Shameful. Don't use mercury. This isn't the 1800's and this isn't the third world. Irresponsible tactics like this give us all a bad name and jeporadize the environment. Wake up man!!


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## OMG

Thats a lot of great info.
Thanks blueduck.


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## JOE S (INDY)

Just something to keep in mind -

In North America "Black Sands" are usually considered to be Magnetite and Hematite. I have found that often times there is also rust (Iron Oxides) present in the concentrates and on the surface of the gold. I use Muratic Acid as an inexpensive, simple, surface rust remover. 

Magnetite is quite magnetic and a simple magnet will easily remove it from concentrates. Fanning concentrates, under water, near and past the magnet will allow other constituants to mearly pass by and drop to the bottom. 

Hematite (and some other minerals) are slightly, slightly magnetic and can just be picked up with a "Neo" (or Super) magnet. Pan these removed minerals to seperate any possibly surrounded and trapped gold or (sometimes) magnetic Platinum.

Now, another "black Sand" rarely mentioned is non-magnetic Manganese Dioxide. http://en.wikipedia.org/wiki/Manganese_Oxide 
MnO2, if present, often encapsulate a piece of gold making the resulting shiny black grain lighter in the pan than gold but heavier than Magnetite or Hematite. 

MnO2 is brittle and can be shattered through direct crushing or thermal shock. Crushing is easier and faster.

I mine on the southern edge of Denali Park and MnO2 covered gold is sometimes found there. The miners long ago threw it away and I collect all I can.

Friends in Australia have mentioned to me that the black sands there are not iron based. I suggest that you confirm what you have before you start if you live in exotic areas.


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## aflacglobal

> often encapsulate a piece of gold



Until recently i didn't understand the complexity of raw earth minerals and metals. I wonder how much of the black sand concentrates that people dispose of is still loaded with values. I think it would surprise people that specks of gold 10 um and smaller could be trapped inside the sand itself.
Not all can be reached by direct crushing or thermal shock efficiently.

For reference a red blood cell is about 9 um.


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## Irons

aflacglobal said:


> often encapsulate a piece of gold
> 
> 
> 
> 
> Until recently i didn't understand the complexity of raw earth minerals and metals. I wonder how much of the black sand concentrates that people dispose of is still loaded with values. I think it would surprise people that specks of gold 10 um and smaller could be trapped inside the sand itself.
> Not all can be reached by direct crushing or thermal shock efficiently.
> 
> For reference a red blood cell is about 9 um.
Click to expand...


In nature, visible Gold is quite rare. When dispersed in rock, the fine Gold Particles are anything but Gold colored.

Around here, most of the coarse Gold was recovered from streams by the time of the Great Depression.

Think small.


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## blueduck

In the Salmon river here in central Idaho, there is a gold the miners refer to as "float" gold, also "2 sided" gold for under the scope it appears to be flat and refuses to lay down in a sluice or pan if the flow rate of water is at all notable....

encapsulation in black or brown is often referred to as a telluride but both contain Au and is the way the Chinese mined the gold from the river in these parts. Many "mud ovens" can still be seen across the river as you drive down Highway 95 and modern day idiots still believe the Chinese only used these ovens to "bake bread" yet a few old timers watched as kids how they stood there and sifted the concentrates into the ovens and then panned out the gold afterwards [or used acids] cause the flame/heat cracked the tellurides and allowed the gold to be exposed.

The Massacre near Salmon Idaho in the mid 1930's just before the Chinese left camp for the winter yeilded no gold in camp, but those miners took out over a million dollars the previous year from the same area, and the mud ovens are still present and the site is now a national monument under the forest service or parks..... ergo that gold is still there hidden somewhere.... anyhow some of the folks who partook in that masacre still have descendants living in the area and they claim no gold was found and the massacre was wrong and brought on by "gold fever" and racial tensions, anyhow over 30 miners were killed in that spree. In a side note, my dad tells of 2 chinese who wre cooks in a logging camp near where he grew up, and the first year they took out with them for the winter over $20,000.00 during the years just before the depression, and the next year rumours were amonst the loggers that those 2 had a "lost mine" near the logging camp, different loggers stayed out of camp to watch andsee wheere one or the other might go to for mining the gold but no "hole in the ground" was ever found... my granddad ran cattle on those hills and found several old shafts but they were older than the logging camp era and the second year the cooks were there one died of the flu that winter and the other was killed in a poker game in San Fransisco, so the legend of the lost mine abounds to this day, though i have my suspicions from my research, or learning from a few old miners around here, that those fellas used the logging camp oven to "cook the fines" and collect the gold during the year whilst they were cooking...... excellent cover!

in all the float Gold in the salmon river has been analized at different times by the College of Mines at the U of Idaho and if a person had a dump truck load of concentrates they would be wealthy enough to retire to just about any island in the Fiji's it is perhaps the richest of the known float gold in the lower 48, but trapping it out of the river remains the one key ingredient that no one has come to figure out how to accomplish, even when you dig a bucket full of cons out of a bank and try to wash it down to size the float gold just rinses away as you try to remove the gravels you dont want..... it is maddening cause you can see it there in small quantity, and the size is about 15,000 of the flakes to an ounce... give or take 40 pieces..... so it aint as small as some other specimens, but it's up there.

There is also some blacks in the river that are used in making the solid rocket fuel for the space shuttle...... on a shaker table they appear green among the black particles, about 3 inches in a 5 gallon bucket will weigh heavy enough to rip the handle out when you try to lift it..... there is one mine near Riggins that was producing this a few years back.

William
Central Idaho


----------



## aflacglobal

Good story Blueduck :wink:


----------



## blueduck

The stories are true, there are a diminishing number of folks who remember the actual events, for both of them happened back around the time my dad was born, and he is 73 years upon the earth this past June. though I must recount the massacre as actually happening in 1887 on the Salmon River by a group of whites from Oregon [some of whom were undoubtedly my families neighbors at the time].

But the fact that the Chinese had immigrated to this area looking for gold and found the same is a fact that can not be overlooked, they were at the time probably the most dedicated folks who relieved the earth of more gold than those Spaniards who were on conquests for the yellow metal. They slaved away then at a pace that today would set most soft bellied American workers on their deathbeds in less than a week. They had the most advanced knowledge of how to extract the metal of any cultural as a whole, and could keep their mouths shut about finding the precious yellow metal to keep the "gold rush" down for obvious reasonings.

That there is a mountain of black telluride in the wilderness found by a hunter and claimed, though the claim was struck down because it was "cherry stemmed" into the one of the wilderness tracts that abound in this area is a fact that cannot be refuted and that mountain would provide enough gold today to bring the price down considerably more than likely.... it is the probable source of much of the float gold and telluride in the salmon river today, though I can not know that as fact, it dont take a genius though to put 3 and 2 together and come up with 6. Extracting the gold economically is still the problem faced, among the other problems of trying to stay in line with all the regulations heaped upon the small scale miner and other miners as well under the guise to "protect" the environment, though other industries do more harm than that of modern mining.

History only remembers what those in power wish folks to know, then the truth that might have presented a correct viewpoint is buried or hidden and the people have to discover the real facts once again.

Soapbox stances get slippery when wet.

William


----------



## OMG

After some time off, I've decided to look into a different way to separate the iron from the sand.

So.. Does anyone have any references for plating Iron?
There is lots of info about plating, but none for iron. I guess there isn't much use for iron plating. I was thinking that maybe there would be a way to dissolve iron and plate it out all at once in one tank. Using the FeCl2 or whatever as the medium to dissolve and move the iron to an electrode.

I'm hoping that maybe with the current flowing (making the iron plate itself), the just plated iron will be reluctant to be dissolved again.


----------



## Lou

If there's a mountain of telluride sand out there, let me get my plane ticket buddy. Gold tellurides are the richest yielding of all gold ores, and I'm not afraid to mess with them. I need to talk to you more Blueduck.



Lou


----------



## blueduck

Lou said:


> If there's a mountain of telluride sand out there, let me get my plain ticket buddy. Gold tellurides are the richest yielding of all gold ores, and I'm not afraid to mess with them. I need to talk to you more Blueduck.
> Lou



Its there, but its smack in the middle of the wilderness boundaries.... get congress to change the wilderness act, and the forset circus to change the FLMPA and it would might be a mad rush t file a claim on it, but it aint gonna happen in this lifetime more than likely..... and the penalty for trying to do something in the wilderness boundaries are such that it aint worth the risk.....

William


----------



## Irons

blueduck said:


> Lou said:
> 
> 
> 
> If there's a mountain of telluride sand out there, let me get my plain ticket buddy. Gold tellurides are the richest yielding of all gold ores, and I'm not afraid to mess with them. I need to talk to you more Blueduck.
> Lou
> 
> 
> 
> 
> Its there, but its smack in the middle of the wilderness boundaries.... get congress to change the wilderness act, and the forset circus to change the FLMPA and it would might be a mad rush t file a claim on it, but it aint gonna happen in this lifetime more than likely..... and the penalty for trying to do something in the wilderness boundaries are such that it aint worth the risk.....
> 
> William
Click to expand...


Getting caught even hauling a backpack of 'dirt' will land you in big trouble. Some Feds tried to bait me into working a wilderness area. It was posted and I told their agent provocateur that I wouldn't even set foot in the place.


----------



## goldsilverpro

OMG. 

I have iron plating in some of my plating books. I'll look it up.


----------



## OMG

GSP,

That would be great. Even a reference to a good book or something would be helpful.


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## goldsilverpro

OMG,

It seems that every aqueous iron plating solution on the planet only works with ferrous iron (II). The ferric iron (III) produced from dissolution by acids won't work. In order to keep the iron (III) in solution, the solution must be fairly acidic and the iron (III) won't deposit out of this acidic medium. Instead of plating, only hydrogen would be generated at the cathode. 

The iron (II) will plate from an acidic medium. Therefore, to deposit iron, you will somehow need to first reduce the iron (III) to iron (II). I found no good schemes for doing this. One company was researching the use of bacteria to perform this reduction.

If you can affect this reduction, there are plenty of plating formulas that use iron (II). Most use the chloride or the sulfate. Here are a couple:

CHLORIDE:
Ferrous Chloride, anhydrous - 40 to 60 oz/gal
Calcium Chloride - 25 to 25 oz/gal
Temp - 190 deg F, minimum
pH - 1.2-1.8
Current Density - 20 to 80 amps/sq.ft.

SULFATE:
Ferrous Sulfate (FeSO4.7H2O) - 32 oz/gal
Temp - 90 to 150 F
pH - 2.8-3.5
CD - 40 to 100 asf


----------



## Irons

Find it the fertilizer section. Light green crystals. Cheap. Used to precipitate Gold.

Have another cuppa. 

Lower the Ph with a small quantity of Sulfuric acid. Put your Black Sand in an acid proof cloth bag with a Carbon rod for an electrode in the center. Connect the carbon rod to the positive (red) wire. Use an old computer power supply with enough resistace to limit the current to a safe value for the supply. Use an Iron Cathode. If you see Hydrogen coming off the Cathode, your voltage is too high, then add more series resistance. The redox potential of iron is -.340V referenced to Hydrogen.

Add a small amount of Hydrogen peroxide. This cell will produce it's own H2O2 once started.

Go watch the grass grow.

Please correct as required. I probably screwed up something.



Tweak as required.


----------



## OMG

Thanks, I'm looking into it further. I'll keep you posted on any developments.


----------



## OMG

Well, I think I may have found a way to reduce the Iron(III) to Iron(II).
2FeCl3 + Cu -> 2FeCl2 + CuCl2
found it on wiki under iron(III) chloride
-now I need to find a way to bring the Cu back so it doesn't get consumed.

Hey (Irons), do you know the equation of how the H2O2 is produced during plating?

I'm also wondering if it is possible to use the process:
FeCl2 + H2SO4 -> FeSO4 + HCl
and plate the iron from the sulfate instead of the chlorate, seeing as H2SO4 is much cheaper than HCl. (there also may be a way to regenerate the H2SO4)

The reason I'm asking about how much H2O2 is produced is because in principle if I'm taking away the iron from the iron oxides, I will also have to take away the oxygen, and using H2O2 to get rid of oxygen seems like the easiest way.

hmm. maybe the extra oxygen will oxidize the pyrites somehow.


----------



## Irons

The oxygen is formed at the Anode during electrolysis thereby making H2O2. In the old days, H2O2 was made commercially by the electrolysis of a dilute H2SO4 solution.

H2O2 will greatly speed up the decomposition.

You can try it yourself by taking some black sand and putting it in battery acid and watch the difference when H2O2 is added.

H2O2 has a very high oxidation potential.

Making it directly by electrolysis in place is a bit cheaper than buying it. Electricity still costs money and electrolysis is not very efficient.

Results will vary. Not all black sands are the same.

Don't do this in a living area or confined space. If there are any values in the black sand, there is probably Arsenic as well. This technique will generate arsine which is a gas and it will kill you in short order. Even low levels of Arsenic will accumulate in your body. I had to go to the emergency room this summer from arsenic poisoning, and I was trying to be careful. If you don't know what you are doing, don't do this. You will need to run the exhaust through a scrubber if you do any quantity. The neighbors won't be happy if they find out they are being poisoned.


----------



## OMG

My attempt to plate iron will have to wait until I get some better equipment.
Does anyone have a plating setup? What kind of equipment is good to use?
I would like to get a power supple that allows me to choose the voltage and amperage, but they are pretty expensive. I also need an electronic ph tester or something.
But anyways. I think I have good news.
I appear to be "plating" rust. lol. (hopefully its not just funky looking copper)
I used a copper anode, iron cathode,
iron chloride and copper chloride electrolyte, with a wee bit of salt in it, and HCL.
And I have a bunch of black sand in the bottom of the container.
I put the battery charger on 12V,12A and let'r rip.

Lots of hydrogen is coming off the cathode, so the stuff thats plating there is very spongy. (Thats why i'm not 100% certain its rust. It could be just spongy copper)

I'm getting a white powder forming on the copper anode that sloughs off and dissolves eventually. I think it is CuCl. Which apparently will lower FeCl3 to FeCl2.

And something else I can't explain is why bubbles keep coming out of the black sand. (not too much, but definitely there)

Anyway, I'll let the reaction go for a bit more and then check to see if the cathode is actually rust, or if it's just spongy copper.

Chime in if you can shed more light on whats going on. lol


----------



## lazersteve

OMG,

I think your spongy substance is copper. 

The white stuff sounds like copper (I) chloride to me.

Photos would help.

Steve


----------



## OMG

It sure is Copper.
The experimenting continues....

I'm still curious as to what was bubbling up from the black sand.
oh well.


----------



## OMG

Now I think I have it!!!
Iron is definitely being deposited at the cathode. I wiped it off and studied the particles. And I put some HCl on it and it turned bright yellow.

The iron is also being suspended in the electrolyte. Its a black cloudy mess.
The anode seems to give off CuCl at the start of the reaction, but slows down later.

So I should be able to set something up to continuously filter the suspended iron from the electrolyte and pump the clean stuff back in.

I imagine if I cut the voltage down to the appropriate amount, it would plate the iron instead of deposit it. But I like how fast it is depositing it. Man there is ALOT of iron in sand.

Now I will let it go and keep taking out the iron being collected at the cathode. I hope the electrolyte is not degrading itself.


----------



## OMG

Heres some pics.


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## OMG

The cell will deposit copper too, but it only seems to after a while. I think it does this when the supply of iron starts to diminish. It deposits the iron as well as copper. It deposits very quickly too. within a minute or so there would be 1/8 inch of goopy iron on the anode.

As far as I can tell the cell creates HCl. I only added about a 1/2 cup of HCl to start with, and after a few hours it was fuming and smelt like HCl. (also: when exhaled over it a mist formed like it does over concentrated HCl) The electrolyte was also getting hotter by itself.

When the reaction slowed, I added more fresh sand mix to it, and after a while bubbles started coming out of the sand and the reaction sped up again and drew as much current as it could (12 amps).

It was kind of weird because the amount of current it pulled kept fluctuating. It would go from very little to maximum within a minute or so. And other times it would stay constant.

I'll have to try to figure out the chemistry behind it and get it set up better. Then see if I can pull out only the iron.

I think the way the cell is now, it will dissolve and precip/deposit out any metal (up to a certain point). When I inspected the iron closely I saw little gold colored spots. I'm guessing that was probably just some pyrite that happened to be at the wrong place at the wrong time when the iron was depositing itself. (I hope it wasn't gold)

But anyway. I think this is a major step in my quest. I'll keep posting more developments.


----------



## goldsilverpro

OMG,

I can see your thinking, on the copper, but, it's expensive, and it seems to complicate the situation. The iron chloride may not be necessary either. 

Maybe try an inert anode, like carbon. With an inert anode, there would be a maximum of oxygen/chlorine evolved and H+ ion entering the black sand. This highly acidic H+ layer, in the black sand, may perk up the dissolving.

Have you tried just using salt alone, diluted HCl alone, or a NaCl/HCl mix, with no metal chlorides added. A plain 10%, or so, sulfuric solution might be interesting. With sulfuric, you might try a lead anode. 

If there's a lot of hydrogen gassing at the cathode, there's an equivalent amount of OH ion entering the solution. This could tend to neutralize the acid and also is, most likely, reacting to produce an iron hydroxide or oxide (most probably) at the cathode surface.

Just some ideas. I don't have a way of trying them out.


----------



## OMG

I have tried plain HCl and NaCl, with a variety of electrodes (and other additives) with no luck.

I tried the current cell I have set up with carbon electrodes and both electrodes are emitting gas. I assume chlorine and hydrogen - which is what I don't want.

The cost of the copper would be small if it allowed me to remove the iron effectively. The copper anode in the setup provides two things (1: puts CuCl in solution which will reduce Fe3+'s to Fe2+'s, and 2: prevents the escape of chlorine from the cell. Also if I'm not going to actually plate the iron, I could run alternating current through it and make the copper plate and deplate itself on both electrodes at the same time. If that would work then the copper would still serve the purpose of keeping the chlorine in the solution.

I was hoping my setup would generate and oxidize chlorates which would then be so oxidized that they would release some of their oxygen.

The best setup would be if ONLY oxygen was given off, and the HCl is preserved.

The end goal is actually simple. Just dissolve and immediately precipitate the iron and keep doing that until the solution has reached a point where the iron isn't concentrated in the sand on the bottom, but is spread out through out the tank.


----------



## blueduck

what about adding OZONE into the mix and using the O3 to rust the iron? That at least was my friends idea when he got into the ozone machinery years ago..... an ozone generator is not hard to build, the ones Water Oz builds are really not all that spendy though you need the one that you can hook a bottle up to to get any production from.

there are others, and the one my friend picked up cost him about ten grand nearly 15 years ago...... but he has had fun oxidzing the local town with it [ok maybe not quite but it was designed to clear a 100x100x 20 warehouse out of toxic fumes in 20 minutes or less..... anyhow that too might work for the process and mayhaps at a reasonable rate even.

William


----------



## OMG

I think the ozone would be too expensive.

Some updates,
The only thing being released from the cell are:
Hydrogen: from cathode (a lot of it)
Oxygen: bubbles up from the sand mix occasionally.

The electrolyte doesn't get used up very much from what I can tell,
I left the cell for about a day, and when I started it again it took at least 5min to get going at all, then I added a bit (maybe a pinch worth of NaOH mixed with some water) and within a few seconds it was at full speed again.

Things I still have to fix:
The copper anode depletes itself - and builds up an excess of CuCl that doesn't seem to be dissolving.
I need to setup a good filtration system to filter the iron precipitant quickly into some other vessel. And the filtration system has to handle pumping the chloride electrolytes.

I'm still confused as to what is happening that allows so much hydrogen to be released. (Which should mean that the electrolyte will eventually degrade)
I think its creating H2O2 from the H2O. 
That would account for some of the hydrogen loss, and could explain the bubbles of oxygen. But there seems to be a lot of hydrogen if this was the only thing.
I guess I could let it run continuously for a long time to see if eventually more oxygen would bubble out. (it would have reach about 1/2 of how much hydrogen is coming off). Which would make it a crazy boiling mess.
The only other though I had was that the copper anode (Cu) is being dissolved and reprecipitated as a copper oxide(CuO?), which would account for more oxygen being bound up - which would mean more hydrogen being released.
Maybe next time the cell slows down I will add plain water to see if that speeds it up the same as the NaOH+water did. (wouldn't that be nice)
As it stands now the electrolyte has to be accumulating OH ions somewhere.

Thoughts anyone?
:?:


----------



## lazersteve

OMG,

Have you performed a dry run with your cell setup to determine what the baseline cell (without any black sands in the cell) behaves like while operating?

The hydrogen is most likely from electricity passing thru the water.

The CuCl is soluble in acid medium.

Here's what wiki has on CuCl:

Copper (I) Chloride

Steve


----------



## aflacglobal

> I think the ozone would be too expensive



:?: :?: :?:


----------



## OMG

aflac,
I meant it would be too expensive to buy an ozone generator. Generating ozone myself might be different.


----------



## OMG

After some reading, I see that I am most likely producing chlorates and perchlorates.
Every oxidation step-up of the clorate releases more hydrogen and OH ions.

The weird thing is that the reaction was slow until I added NaOH. You'd think it would have enough OH in it.

The quest continues.


----------



## OMG

I've got a new reaction going.
I think the reaction goes like this:
The iron ore is dissolved by HCl to make FeCl2 and FeCl3 and H2O
CuSO4 + FeCl2 -> FeSO4 + CuCl2
H2SO4 + CuCl2 -> 2HCL + CuSO4
Copper is prevented from plating by
2FeCl3 + Cu -> 2FeCl2 + CuCl2
And the acid is made during precipitation at the cathode (I think)
FeSO4 + 2H20 + e -> H2SO4 + Fe(OH)2

The only drawback I can see to the cell is that it dissolves the anode into and builds up CuCl2 in the electrolyte.

Very little hydrogen is produced now, and the cell is running at 12V and about 6 amps.
Now I need a filtration system to remove the precipitated iron out of the electrolyte.
The reaction seems stable when there is an overabundance of precipitants in the solution.

If theres any chemists out there that can confirm these reactions are probable, let me know. (Particularly about the acid creation at the cathode)


----------



## Irons

something like an aquarium filter.


----------



## mikeore

I am still working on my cell. So far so good. One of my mistakes was using a carbon electrode as the cathode, it degraded very rapidly. I reversed the polarity problem solved, duh. I am also going to change my other electrode from S.S. to titainium. I think that leaching the black sand first then filtering it off is the way to go.
I have precipitated gold and copper out of solution so far with sucess, I am very excited about this so far . Needs a few bugs worked out, but no problem.
Power supply, my problem too. I have been using a battery charger. Found a good one at Ramsey electronics for $219.95. 0-30v / 0-10amp looks like a winner.
I am currently working with black sand this week. I will keep you posted.


----------



## mikeore

Your on it man, I think we are trying to do the same things from different directions, kinda mabey. It will happen.


----------



## OMG

Ya, the setup I'm trying to achieve will dissolve and precipitate the metal oxides simultaneously. Then a filtration system will remove the metal that gets precipitated so more metal can be dissolved.
Mine is not quite there yet. It still requires small inputs of HCl, and I have to find a way to get(or keep) excess Cu out of the solution.

So the cell basically just particlizes the selected metal so it get suspended in the electrolyte and can be removed through filtration.


----------



## mikeore

Have you ever checked out Action Minings' SystemIII ? It uses continous agitation via a motor / paddle combination and a poly filter bag around the collector.
Here are some links to supliers that I have used. Might come in useful.
http://www.smallparts.com/
http://www.amasci.com/supliers.html
http://unitednuclear.com/supplies.htm


----------



## OMG

I have researched more and now have a more complete way to extract the iron out of black sand. It uses copper as a catalyst.

So now the idea is to make sulfates and chlorides of the metals/ores.
The higher metal (copper) will stay as chlorides (CuCl2)
While the lower metal(iron) will be a sulfate (FeSO4) and it will get plated.
Cl2 gas and SO2 gas can be bubbled in which in the end convert some water to H2SO4 and HCl.
Once the iron supply runs out copper will become the sulfate and start plating.


----------



## deserdog

Concerning the mountain of tellurides in th wilderness area. You can prospect in a wilderness area, just cannot use motorized equipment. Many Forest Service people will tell you you cannot prospect in a wilderness area, but it is written right into the Wilderness Act that you can. A wilderness area is not like a national park or monument where you caannot remove anything.


----------



## OMG

Well I guess I'll continue this thread seeing it is a quest.
Even though reading back, I see I was kind of flailing around in the dark. lol.

Here's the method I recently tried and had success in removing "all" of the base metals from black sand concentrates.

Simmer the bs concentrates in hot sulfuric for a while. Things try to come out as more and more water gets evaporated, but no matter.
Then after thats reacted for a while, let cool and slowly dilute. Dilute enough that the liquid can be filtered from the solids.
Then do a final wash in HCl to remove the stuff that the sulfuric couldn't get.

That leaves the solids with no base metals. So I put in fresh HCl (no color change was observed). Then added bleach, and now its sitting. The color did change to a darker yellow that just bleach and HCl make by themselves, so something got dissolved. I left it overnight, and I'll check it today to see if I got any gold.

Then I have to see if regenerating my sulfuric will work. If things go good, I think this will be the method that I will tweak to make perfect.


----------



## Oz

OMG,

My first thought with simmering BS in sulfuric is that it can get very concentrated. Depending on how you dilute it (always acid into water) if you pour water into it and it is concentrated you could get a vapor explosion of sulfuric in your face. 

I’m no expert by any means but I am rather sure that copper will not go into sulfuric and iron has great difficulty. When you say all the base metals are removed what are you thinking you do have left after the sulfuric but before HCl?

I’m not trying to criticize, just understand what you are doing.

Thanks,
Oz


----------



## OMG

Its great to be critical. I take no offense at all.
I have heated bs in sulfuric already(started at 30% conc). I believe that I could dilute it with water (which i did very carefully - sprayed a mist of water over it initially) because most of the sulfuric was used up and were metal sulfates - not much free h2so4 was left
Copper does dissolve in heated concentrated sulfuric apparently. (wiki sulfuric acid). Even if it all doesn't get dissolved, it doesn't matter at this stage. The main goal is to get the vast majority of the metals out while still keeping the gold an pms in.

After heated sulfuric. I thought nothing would be left, but there is something that HCl can get that the sulfuric didn't. I washed the concentrates out then added hcl, and it instantly turned yellow. I'm thinking that sulfuric doesn't attack fe3o4 (? or something) very well, but hcl does. But after I did the hcl wash (left it sit for a while, mixing it up a bit), the next hcl wash stayed completely clear, so there must have been nothing available for it to dissolve. Then I added bleach and it turned yellow. I just checked it during lunch, and it was deep yellow. So now I will find out what that yellow is. It may just be iron that was a being very stubborn, but I'll find out.


----------



## Oz

Great! Different people take it different ways. As long as it is constructive that is how I learn.

I had based the copper comment on something I thought Harold had said before and I knew he did most things hot, but I could easily be wrong. The iron in sulfuric was based on boiling sulfuric in cast iron kettles for some large reactions.

Stepping beyond that, I am more interested in your real world results. I am assuming that you are checking everything with stannous. Something else to think of is that if PMs go into solution the dissolving Fe would precipitate it back out as fine powder.

I’d love to hear more!


----------



## Harold_V

Oz said:


> I had based the copper comment on something I thought Harold had said before and I knew he did most things hot, but I could easily be wrong.


Hot dilute sulfuric acid is used as a pickle for copper. It dissolves the oxides, but not copper. I have personal experience with that process. I don't know about concentrated sulfuric. 

Water and sulfuric combined create totally different conditions. For example, from reading, I learned that slimes that are removed from a silver cell were commonly boiled in cast iron vessels with concentrated sulfuric acid to remove the remaining silver. As long as their is no water, the sulfuric acid has little effect on the iron kettle. It could well be that concentrated sulfuric _will _dissolve copper. I have read nothing to support that it does, however. 

Irons? Lou?

Harold


----------



## OMG

Well, it showed no color with stannous, so it must have been stubborn iron I guess.
I still think its quite impressive how clean the sand is after hot sulfuric.
I'm going to make a ball mill so I can powder the concentrates, and maybe make a secondary gravity separation thing to put the concentrates in after crushing so I can get them even more concentrated.
The quest continues...


----------



## Irons

Harold_V said:


> Oz said:
> 
> 
> 
> I had based the copper comment on something I thought Harold had said before and I knew he did most things hot, but I could easily be wrong.
> 
> 
> 
> Hot dilute sulfuric acid is used as a pickle for copper. It dissolves the oxides, but not copper. I have personal experience with that process. I don't know about concentrated sulfuric.
> 
> Water and sulfuric combined create totally different conditions. For example, from reading, I learned that slimes that are removed from a silver cell were commonly boiled in cast iron vessels with concentrated sulfuric acid to remove the remaining silver. As long as their is no water, the sulfuric acid has little effect on the iron kettle. It could well be that concentrated sulfuric _will _dissolve copper. I have read nothing to support that it does, however.
> 
> Irons? Lou?
> 
> Harold
Click to expand...

Hi Harold, just read this. Sorry for the delay.

If you add Hydrogen Peroxide to dilute Sulfuric Acid, it will dissolve Copper. Electrolytic Copper plating cells with dilute Sulfuric have been used for a long time. The electrolysis generates Hydrogen Peroxide at the Anode and facilitates the process in combination with the electrical potential.
GSP has a lot more experience with plating technology and I'm sure he can add to this.

I think if you boil the dilute Sulfuric to remove all oxygen from the solution, the Copper will take a very long time to react. I just recently did a test with some Copper wire in dilute H2SO4 and the solution has barely turned blue after 2 months. I attribute that to air contact and a small amount of residual Hydrogen Peroxide.


----------



## Harold_V

Irons said:


> I just recently did a test with some Copper wire in dilute H2SO4 and the solution has barely turned blue after 2 months. I attribute that to air contact and a small amount of residual Hydrogen Peroxide.



The lack of reaction is pretty much in keeping with my experience. I boiled heat treated beryllium copper springs to improve surface finish--which it did, but all activity ceased when the oxides were gone. 

The real question is does concentrated sulfuric acid react the same way? It was stated that it does dissolve copper. I wonder if it does without electrical potential---I'm somewhat familiar with that process, having operated a copper cell briefly when I was trying to reinvent the wheel!  

Thanks for your comments, Irons. 

Harold


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## Platdigger

Gajda, states in his book, that boiling concentrated sulfuric acid will eventually dissolve most every metal incuding rh to the last trace, except for gold.
Randy


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## Irons

Oxygen is a key player in corrosion. 

Sodium Sulfite is added to boiler feed water to scavenge any dissolved oxygen, thus substantially reducing corrosion.

If you read patents regarding the dissolution of PMs, Oxygen is often cited as one of the reactants. This would also apply to many other elements.

Now, on the other hand, If you add Hydrogen peroxide to con. Sulfuric, you have a completely different animal as we have discussed before. That will become a very corrosive and possibly dangerous reactant.


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## AuMINIMayhem

In reference to the "floater" gold going down stream, I wish I was in the area. I know you said the flow rate is quite high, etc, but even if you could skim off "some" of this via a pump or trough type system, would you not be able to run that water through some sort of centrifugal separator? My how I would love to get my hands on just the water..

Another thing I have considered with processing black sands is lN2, yep.. liquid nitrogen.. flash freeze the cons and drop them into boiling water (let any leftover lN2 run off first or you may have quite the eruption on your hands).. naturally this would have to be done in a very well ventilated area as Nitrogen binds as well as displaces oxygen very quickly. Don't get much of a warning before you pass out  ...

I'm currently working with a small Keene "blue bowl" however, just based on the physics, I think something along those lines could be brought up on a much larger scale with some "modifications" of course.. but the phsyics speak for themselves. I'd really like to get my hands on a spiral seperator or three and do some experimenting.. 

Thing real crux is, how fine are you willing to go before you're ready to let it slip through your hands? If you were to do a test on the water itself I'm sure you'd find that gold ions in it as well.. (we all know about gold ions in seawater, right.. although it only amounts to a measly, what 8ppb?)

I'm finding that there's a limit that you have to set for yourself as far as how "small" you're willing to go.. once that is established, go for anything larger.. it becomes expnentially more difficult and expensive squeezing blood from a stone 

Derek

(it feels good to be back  )


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## amosfella

I was thinking about the person that said that he was watching a lot of flake gold float away while trying to pan. Could one not put the stuff dug into a bucket with some water, and shake the bucket up, or stir it until the gold floats off, and then pour the water through a cloth vacuum bag, then go about panning the remainder??


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## Elfs

amosfella said:


> I was thinking about the person that said that he was watching a lot of flake gold float away while trying to pan. Could one not put the stuff dug into a bucket with some water, and shake the bucket up, or stir it until the gold floats off, and then pour the water through a cloth vacuum bag, then go about panning the remainder??



Or use the flotation method and collect the foam to remove the gold from samples.


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## Lou

Since this thread was resuscitated quit recently, I should answer the question of sulfuric dissolving copper.

The answer is yes, hot (>100*C) concentrated sulfuric acid will dissolve copper with much stench of SO2. Sulfuric is not an oxidizer at room temperature, but it is when hot!


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