# Can Gold Dust be refined by using Aqua Regia



## TheWildCatMine (Dec 28, 2012)

Hello everyone. Don't know if anyone could help me here. We are mining very fine gold dust and are currently using a blue bowl to extract the Gold Dust at the moment. Has to be used very slowly to obtain the dust we are getting back. Very good amounts. But, the dust still contains fine sand and waterlogged fine black pieces of wood in the material. All Magnatite has been removed prior to using the Blue Bowl. I was wondering if boiling the Gold Dust in Aqua Regia would purify / combine /coagulate the gold so we could have a finished product and get more for it. Instead of having to sent it out to a refinery for a commission or just try to sell it at a reduced rate with out really knowing its full purity potential. Help. Would appreciate anyone's experience.


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## butcher (Dec 28, 2012)

First of all I would make sure I had gold and not pyrite (fools gold).

Not that you do not know the difference, but I have seen so many people who think they have struck it rich, and some of these guy seem to be masters at separating pyrite from other material.Which to me would be a lot harder than panning gold.

when you mention the wood with your gold it makes me wonder if you have pyrite and think it is gold.

The water logged piece of wood the yellow pyrite with it, and all of the big heavy rocks would be dumped from my gold pan very early in the panning stages, if you have wood it is light even waterlogged and will pour out of the pan long long before gold even thinks about moving from the bottom of the pan.

Yes placer gold can be refined, but I would do a little more than just dump it in acid.

Pyrite would make you think you had gold, even in acids, but would give you very confusing results and little or no gold.


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## Madraykin (Dec 30, 2012)

Somewhat related, I have acquired some gold dust that has been ablated off of some sort of component using a class 4 YAG laser. The dust is VERY fine and jet black. I'm certain the process for refining and purifying this isn't covered by Hoke, at least not in it's entirety. I'm thinking there's most likely trace amounts of lead, nickel and copper, but I've seen the process and am fairly sure the majority is gold. I have enough of this stuff to fill a quart jar. Do I a) melt a small quantity to molten form and pour into water to form shots, roll, cut, twist and drop into nitric to remove base metals or b) clean first with boiling lye solution, filter, rinse with hot water a few times then go with nitric and the usual processes that follow or c) lye boil, rinse, rinse dry, melt and then nitric? 

I will be quite flaberghasted if this has been covered already in another thread. Thanks in advance.


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## qst42know (Dec 30, 2012)

> Somewhat related, I have acquired some gold dust that has been ablated off of some sort of component using a class 4 YAG laser. The dust is VERY fine and jet black. I'm certain the process for refining and purifying this isn't covered by Hoke, at least not in it's entirety. I'm thinking there's most likely trace amounts of lead, nickel and copper, but I've seen the process and am fairly sure the majority is gold. I have enough of this stuff to fill a quart jar. Do I a) melt a small quantity to molten form and pour into water to form shots, roll, cut, twist and drop into nitric to remove base metals or b) clean first with boiling lye solution, filter, rinse with hot water a few times then go with nitric and the usual processes that follow or c) lye boil, rinse, rinse dry, melt and then nitric?



I would think some tests in a spot plate may help determine what processes if any are necessary.

Incinerate a small amount and divide it up.

1. Prove gold content. With AR and stannous.

2. Is HCL effective.

3. Is nitric effective. And then a bit of salt to test for silver.

This is where I would start.

This is for the laser dust question not ore. Edited to clarify.


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## Gratilla (Dec 30, 2012)

IMO:

1) Leach with AR (or one of the other chloride leaches).
2) Solvent extract with butyl diglyme.
3) Precipitate with oxalic acid, MSB or ferrous sulphate.
4) Press powder into ingot/coin shape of your choice.

If you're reasonable careful, you should be able to get 99.99 gold.


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## TheWildCatMine (Dec 31, 2012)

Hello Butcher. Thanks for the info/reply. You have some very interesting points. Yes we are new to this. So, you may be correct that we may have pyrite instead of gold. However. The location is have been proven by a Old Timer friend who gave up his claims. Never had a chance to speak to him regarding this area, as he is now deceased. We are next to a stream that has nuggets in it and are digging on a bench with very red dirt. The rocks that we remove from this Iron enriched dirt are a deep Yellow/Orange color and are very heavy !! That was my first indicator that gold was present in this bench after panning it. We dig the dirt from the bench classify it through 1/4 inch screens there, then bring it home and classify it through 1/8" mesh 16 mesh/ 30mesh we also have classifed allot of this material with 100 mesh. But, started processing this Gold Dust from the 30 mesh level. This allows for very fine pieces of waterlogged pieces of wood to get through. When screening the concentrates with a garden hose nozzle over a 5 gallon bucket. If we use the 100 mesh I am sure we would get most of that Water Logged fine bits of wood out. The final concentrates that we get are a bronze gold color mixed in with black spreckles of waterlogged wood. You see, we are not panning this material. We only panned at the beginning to test for gold presence in the dirt and like you stated it got rid of the water logged wood.

I think the best thing at the moment first. Would be to take cross samples of these large jelly jars of gold dust and have Fire Assay perform on all the samples. What do you think???

You say: Yes Placer gold can be refined, but, I would do a little more than just dump it in acid. What would you suggest if this was your gold dust???? Your detail answer would be appreciated !! I know gold dust can be sold but, the Fire Assay would at least determine what percentage % of gold there was in this dust.

Well, you have a good point that needs to be proved first. And that is, that this material is not Pyrite Fools Gold. Man I hope it is not. There is allot of this stuff present in the bench we are digging. I will have the Fire Assay done on a cross samples of these Jelly Jars of material we are extracting with the Blue Bowl System. And if we are lucky we will eventually move up to a Global Mining Solutions: RP-4 Gravity Shaker Table. Unless you have other recommendations. We are open to learning !! And appreciate all input.

Thanks, a bunch. Butcher / Madraykin / qst42know / & Gratilla

Sincerely, The Wild Cat Mine.


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## butcher (Jan 1, 2013)

I have seen pyrite in our river sand that looks like half the sand is gold, you can find gold in any stream and river here, as I live in a region rich in its history of gold production, most new miner mistake pyrite for gold, it is very easy to tell the difference, you would not need an assay, just a little education, pyrite can come in several forms but usually small soft flake that you can smash to pieces or smear to powder with the flat of your pocket knife, or pyrite crystals that will break when crushed, Gold is malleable and will flatten when hammered without falling apart, pyrite is brittle, gold will also be much heavier, Pyrite is light and will pan out of your pan before the black sand, gold will stay in the pan after you pan off black sand, gold is not plentiful (even in rich bearing areas) (although you can hit good pockets), pyrite is very plentiful around here it is everywhere we have decomposed granite with mountains of about half pyrite. if roasted pyrite will change colors, you will smell SO2 gas burning off, placer gold will not burn off sulfur compounds.

Try this in a gold pan, put a few small pieces of lead say (similar in size to your gold), throw in a hand full of sand, some of the gold your panning, a small piece or two will do, a handful of gravel and bigger rocks up to fist size would be ok, now have a big tub of water, practice panning, pan your material into the tub, nothing is lost in the tub, the pyrite will pan of first with the bulk of the material, you should end up with some black sand, your lead and any gold in the pan, now panning carefully you can remove the black sand from the lead and gold, if you lost lead into your tub you need to practice your technique, when you can keep all of the lead in the pan your keeping your gold, lead is a bit lighter than gold and will pan off before your gold.

Placer gold will melt to a button that can be hammered flat, pyrite will not.

I am assuming you are dealing with placer gold.

Hokes book is a good source to begin your study on recovery and refining your gold, we can give you some tips once you get a better understanding of the basics.

P.S. I sure hope them jars are full of gold.
But I also learned hopes do not pay the bills.


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## TheWildCatMine (Jan 5, 2013)

Hello Butcher. OK, tried taking some shavings of lead with a metal file and placed the fine shavings of lead into my Garret Gold Pan. Managed to keep both of the lead and the gold dust in the pan while the larger rocks and stones where first to go and very little of the Magnetite was left. So your test is a good one. Thanks for the cool info. Never thought to test for gold in this manner. But, it just goes to show you that there is always someone who possess more & better techniques if one is will to listen and learn !! Thanks a bunch. 

Today I took some Hydrochloric Acid and did a acid test on the gold dust. Yipee !!! The gold dust didn't disappear or fizz away !! And no Rotten Egg Smell . So that confirms that what my partner & I have found is a profusive gold dust deposit on this bench. Yes it is a placer area. Right next to the creek. However being that we do not possess a RP-4 Gravity Shaker Table at this time. As they are $1,145.00 we are producing quite a bit of Gold Dust with the "Blue Bowl" but, tones of time and manual Snuffer Bottle time to acquire the Dust......Uggggh........Laughing.....This is truly the easy way compared to how the "Old Timer" used to collect and compile their Gold Dust.....Man I have allot of respect for those fellas !!!! 
The reason this is compounded, is the Gold Dust we are finding is very fine. But, profusive in its quantities in the Hard Pack we are digging. The stones in the hard pack are from 1/8" to 400lbs. in size that we have so far had to contend with in this bench. But, exciting to say the least. 

This is a high elevation area so the last time we where able to go out was late Nov. 2012 by the time we where finished that day. I stopped and asked my partner how cold he thought it might be because even though the great physical exertion, I told him my body was becoming stiff, and he stated 29 degrees. By the time we crossed the stream and got out our rectangular Rubber Maid Rough and Sturdy containers of dirt back to the Jeep and got all out gear in and where in the front seat it was 23 degrees and by the time we traveled 2 miles it dropped to 16 degrees. With my heater not working correctly !! And 40 miles to go to get out of the deep heavy snowed tundra. Man naughty !! Laughing... I am living proof that gold can make you stupid too !! LOL.....

Because I am new to all of this Butcher. I have one question. That encompasses many. What exactly does Aqua Regia do to Gold Dust when you place the Gold Dust in the Flask and heat it to boiling point????? What is the final result. Does the small particles of Gold Dust turn into gold flakes??? Coagulate or drop. Or small balls of purified gold??? Does this process purify the gold??? How do you separate??? Dying to know.....I have experience working and cooking particular Acids & Metal Salts for infusion & Carbonation of Gemstones. But, never have used Aqua Regia. And never experienced the effects it has on gold as I have never had actual gold before. Your answers would provide allot of insight that would be most appreciated. If you have a bit of spare time.

P.S. OK, will look into purchasing Hoke's book. We want to get a grasp on being able to properly refine the gold we are mining. Thanks a Bunch once again. Glad to be part of this great forum for folks out there what truly need to refine their own......

Sincerely,

Erik Martinez
The Wild Cat Mine in the Highlands
Of Salmon, Idaho.


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## jimdoc (Jan 5, 2013)

Hoke's book can be downloaded here;
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=16555#p167229


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## butcher (Jan 5, 2013)

There is a free download of Hokes book on the forum; Action mining also sells the book if you want a hard copy.
I really like my copy of Hokes book, I bought it from action mining, I have add so many notes in the book I may have to buy me another.

From your description it does sound like gold, try the test below.

Normally I would in-quarter the placer nugget gold with silver (melting 3 parts silver to one part gold), then pouring the melt into water to make shot (cornflakes).
(If this is fine powdered gold you may get by without this step, but I would do a few small test tube experiments before committing to a large batch.

Nitric acid diluted 50:50 with water is used to dissolve the silver and base metal from the gold.Gold does not dissolve in nitric acid (note to any extent at all see comment below).

Aqua regia is used to dissolve the gold into solution (the acids remove electrons from the gold atoms) and the gold forms a dissolved solution of yellow colored gold ions (a dissolved salt of gold), this also dissolve the very little metal impurity that the nitric could not get to, the nitric acid content of the aqua regia acts as an oxidizer (it actually oxidizes and dissolves a tiny bit of gold, but in nitric acid alone the gold does not dissolve to any extent and may plate back to the gold, but when nitric acid and hydrochloric acid is used Aqua regia, the tiny bit of gold the nitric dissolved froms a chloride bond with three free chlorides from the HCl acid, making AuCl3, then nitric and HCl continue until the gold is dissolved or the acids are spent.

after we get the gold into solution we must get rid of any free nitric acid in solution to get our gold back (we can limit the amount of acid we used or make sure it is spent dissolving gold), if we have free nitric acid we can evaporate the solution three times, or add gold to use up the acid, or use sulfamic acid (some use urea I do not recommend its use), it is normally best to use a combination of these procedures to work with.

then we can precipitate the gold from solution (adding a chemical reagent selective for gold that will give the gold atoms back an electron ant let the gold form powders of fine brown gold that will settle to the bottom of the solution, the solution will hold the minor salts of other metals and acids. 

The gold powder is washed in a procedure intended to dissolve salts of metals that may have also precipitated, and many times the gold is refined again for a very high purity.

I have simplified this for discussion, you will get the details and a better Idea when you read hokes book.

after you read Hoke and get a little more understanding and you do some of the getting acquainted experiments you will find in the book we can help you through the process of refining your gold.

P.S. do a stannous chloride test on your gold, a flake or two can be dissolved in a test tube, or other small vessel, HCl/NaClO (household bleach) can be used to dissolve the gold (heat to drive off free chlorine oxidizer), test the yellow solution for gold, you can dip a Q-tip in solution and add a drop of stannous chloride to see if it turns violet a positive test for gold. Stannous chloride can be made with 95% tin solder and HCl, there are also other tests like the ferrous sulfate crystal in a spot plate (ferrous sulfate which you can also easily make), but you will learn more of this as you get further along.


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## nickvc (Jan 6, 2013)

I love to read these threads and am truly pleased when someone's hard work pays off and they do find gold. Unfortunately living in the UK the chances of finding any decent amounts of gold is slim to nil as we are a small country, have been highly populated for millennia and most of the good was mined and plundered by the Romans just under 2000 years ago  
The other problem is any decent deposits left would be counted as crown property, the governments, and I'm sure they would exercise those rights fairly swiftly :shock:


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## butcher (Jan 7, 2013)

But look at all of the Roman 2000 year old gold coins you could find, or maybe even a stash of gold coins Robin Hood hid in the woods.

Wish I could pan one of those instead of the almost invisible speck of gold, I find in my pan after sitting in freezing water all day.

The grass does seem greener on your side of the fence, from my side. :lol:


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## nickvc (Jan 8, 2013)

butcher said:


> But look at all of the Roman 2000 year old gold coins you could find, or maybe even a stash of gold coins Robin Hood hid in the woods.
> 
> Wish I could pan one of those instead of the almost invisible speck of gold, I find in my pan after sitting in freezing water all day.
> 
> The grass does seem greener on your side of the fence, from my side. :lol:



Butcher that's covered too it's classified as treasure trove, crown property :shock: 
Admittedly you do get financial reward these days but you rarely get to keep your find.


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## Palladium (Jan 8, 2013)

I like this fellow! He's got a chance to learn.


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## butcher (Jan 8, 2013)

Heck thats what I am sticking around for, to learn more.

Yep seems Uncle Sam gets my gold in the end.
That is if he lets me get the gold out of the "my" ground.

I guess the grass is about the same color on both sides of this big blue fence.


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