Non-Chemical Molten Lead Panning??

[galenrog]

Personally I think the idea of using molten lead to gather gold from placering concentrates is way too much trouble for me. I use commercially available lead free fluxes, kiln brick cut to size and a microwave for small smelts and a backyard propane/oxygen furnace for larger smelts. No need for a big pot of molten anything.

I would suggest a few days of study on the several mining forums that have threads on smelting. Once you have smelted gold, then you can get into the refining game.

I would also suggest "How to Smelt Your Gold and Silver" by Hank Chapman, Jr. An excellent primer on smelting, which is about as far as most miner types go, although I am thinking about reserving several ounces of dore later this year to learn refining with.

Keep it simple.

 

[bswartzwelder]

I have been giving a lot of thought to your question. OK, a little thought....only two brane cells left. One is lost and the other is out looking for it.

First, it seems to me that there was a thread about using a lead based flux for recovering gold from black sands. The flux captures the gold and everything floats on top of the molten gold. Later in the process, the recovered metals are reheated and the lead combines with oxygen from the air to form lead oxide which is a powder and leaves the gold behind.

Second thought, if lead combines with gold chemically, wouldn't solder on circuit boards dissolve some of the gold traces?

I made up several batches of flux, but don't have them in front of me. If you need the formulae, let me know and I'll dig them up and post them here.

 

[NoIdea]

Hi bswartzwelder, thanks for the reply.

I have been giving a lot of thought to your question. OK, a little thought....only two brane cells left. One is lost and the other is out looking for it.

Ha Ha Ha, i know the feeling. :lol:

Second thought, if lead combines with gold chemically, wouldn't solder on circuit boards dissolve some of the gold traces?

Yes, my thoughts exactly, their is a fare amount of gold left behind in the solder, not to mention silver. Though im not sure about the "chemically" bit tho. 8)

I made up several batches of flux, but don't have them in front of me. If you need the formulae, let me know and I'll dig them up and post them here.

I would be very interested in your flux formula.

Thans Heaps

Deano

 

[qst42know]

For flux formulas you should study fire assaying. Some metals combine with lead readily others would need taken away in the molten slag and will need adjustments in the flux chemistry to do so.

 

[bswartzwelder]

Sorry, NoIdea, but right now I can only find 1 formula for flux, but here it is:

1 Pound Litharge - Lead Oxide - PbO
1 pound Sodium Carbonate - Soda Ash - Na2CO3
35 grams flour
150 grams silica sand

This was meant to be used as a flux when trying to recover gold from black sands. If I run across the other formulae, I will post them as well. Let us know how all this works out.

I use a heat gun to heat cell phone boards (outside of course). I use a pair of pliers to hold the boards by one edge. When hot, I hit the edge of the board on a teflon coated baking sheet. Almost everything will fall off when done this way. Because of the teflon, nothing sticks to the sheet. You get all the components, flat packs, gold plated connector points, resistors, and solder. Lots of solder. Until now, I have simply thrown the solder away. Think I'll save if if you suspect it contains gold and silver. Now if there was just an easy way to get the silver off old chafing dishes and the likes.

 

[NoIdea]

Thanks for the reply. This mixture looks very familiar, this mixture reduces lead oxide to lead which then absorbes metals of value and oxidzes the unwanted ones, pooling at the bottom of the crucible. I have used a mixture like this with mixed results, tho it was not with iron sand.

My appologies, my intention is to use molten lead

1 Pound Litharge - Lead Oxide - PbO
1 pound Sodium Carbonate - Soda Ash - Na2CO3
35 grams flour
150 grams silica sand.

Until now, I have simply thrown the solder away. Think I'll save if if you suspect it contains gold and silver. Now if there was just an easy way to get the silver off old chafing dishes and the likes.

Well, from what i understand, lead based solder is being replaced by silver based solder, who and where i dont know, so i treat all solder as it may contain silver, any gold plated pins soldered will have some gold migrate into the solder, not to mention that still left on the boards.

Excuse my ignorance, butt what are "old chafing dishes "?

Cheers

Deano

 

[bswartzwelder]

Chafing dishes are like a bowl which sits in a stand. Under the stand, there is a platform or a really tiny bowl which holds a candle to keep the stuff in the upper bowl warm. These are for partys hosted or catered to by rich people. NAH, I never saw one up close till I ran across some at a secon hand/goodwill store.

I had some other instructions which went with the above flux formula. Here it is:
For every 75 grams of flux, add 30 grams of the black sand. Heat in a kiln to 1850 degrees for about an hour. Pour into a cast iron mold and cover the mold with a cardboard box or a metal pot. The glass produced by this operation will most likely shatter as it cools. The box or pot will contain the shards as it explodes.

If it hasn't already happened, remove all the glass from the lead by smashing it with a hammer. Place the lead into a cup called a cupel (It's pronounced Q-ple not cup-l, and is made from cement or bone ash and has a very thick bottom.) and place it back into the kiln. Heat it with the door open just a crack to 1000 degrees. The lead will combine with oxygen in the air and return back to lead oxide. The remaining button of metal contains all your valuables.

Non Reducing flux:

Chemicals in this formula will not reduce to form any other metal in the presence of gold. There will not be a button of lead present.

50% Ammonium Chloride
25% Sodium Nitrate
25% Borax

Mix equal parts of sample and flux. Heat in a kiln to 1850 degrees for about an hour. Pour into a cast iron mold and cover the mold with a cardboard box or metal pot. Glass produced by this method is likely to shatter as it cools.


Gold is not bright and shiny. Sounds like the gold looks more like sand.


I hope this one may help some as well.

 

[butcher]

From the looks of that flux your making a substitute aqua regia in the melt, it would oxidize base metals as it would be an oxidizing melt, the base metal oxides would be in the glass of the borax, I also believe you would loose some of your gold due to volatility of the gold chloride fumes produced, look for yellow or violet stains in the cooler sections of your furnace.

 

[nh6886]

Hi Deano,

I am wondering if you gave this a try and if so what you results were. I have a few bags of black sand that contain some very fine gold I have tried a few different recovery methods but the black sand is almost as fine as the gold. I made a promise to avoid mercury to the guy who taught me to pan years ago so this sounds very interesting to me. Any way thanks for the thread I think this is the greatest idea/experience exchange I have ever seen and hope to add something worth while someday.

All the Best,
John

 

[kurt]

Hi Deano

I to would be interested in hearing if you have tried anything discussed in this thread & how it turned out

Kurt

 

[NoIdea]

Morning All - Sorry, butt no, nothing to date. I have just made a big move from a small town, 20,000 population, to the country. Fruit trees up the wa-zoo, chicken coop, glass house etc. It's spring here and the place was run down and im un-run-downing it. :?:

The gold part has taken a back seat for the moment, butt once i have saved enough for supply's "i'll will be back"

Cheers

Deano

 

[nh6886]

Deano/All

Only a slight variation to your original question here that was touched on earlier? If you ran your material across a bed of bismuth at say 1000F would the gold alloy with the bismuth?
If it did could I simply cupel the bismuth/gold alloy to recover the gold?
I realize this is different than collecting the fine gold in lead where you started but maybe a workable answer to a common problem.
I know you covered all the safety precautions being addressed and I am sure you know but to anyone who didn't assuring that your blacksand was absolutely DRY would be more important than I could express.
Sorry I know this is flurry of questions but that's kind of the way my brain works.
Any comments or correction are greatly appreciated.
All the Best
John

 

[butcher]

Bismuth will collect the gold similar to lead, bismuth is also used to lower the melting point of metals, a mixture of bismuth and lead can melt at about the temperature of a hot cup of coffee, I think bismuth would probably be more expensive than lead.

 

[nh6886]

Thanks for the reply Butcher,

I hope I'm not hijacking this thread to badly but I do have a couple of other questions.
Will the Bi collect the Au at 1000F or absorb it? (not sure if that's the right term)
If it absorbs it will it be better to cupel it or treat it chemically?
I am starting 1000F because the Bi seems to be pretty low in viscosity at that temperature but as in everything else I am open to advice on this and will experiment as I move forward.
My plan is to introduce the material below the surface with a ceramic tube so that it will float up through the molten Bi.
I have a couple of pounds of Bi on hand that came from RotoMetals it is 99.99 pure and cost about US$22 per pound.
You could add in the cost of one crucible if you received credit for not accounting for the expansion of Bi as it cools thats normally abbreviated as DUMB.
I would use lead if it has advantages other than price?

All the best,
John

 

[butcher]

As I understand it bismuth can be used as a collector in an assay and cupeled, I have bismuth but never tried, I suspect like tin it could collect gold at a much lower temperature, in an assay you are trying to get several metals to oxidize to be able to go into the slag, or you are trying to keep valuable metals from oxidizing in the chemistry melt of the ore and to form a button, collectors like lead or bismuth can help to collect the values into one mass of metal, also you may have silica and other minerals in the melt to get into a molten state to get into slag this is where flux and high temperature of the melt are chosen to get the desired chemistry of the melt to collect values into a button and oxidize other materials into the slag.

What I would do is get some clean gold foils, these could come from a few memory cards using the acid peroxide process to remove the gold foils, use these in small experiments with the bismuth, I would try lower temperatures at first as bismuth has a low melting point and it would lower the gold’s melting point when mixed, unless there is other material that would need oxidizing, or reducing (as in ore or base metals) in your experiment then you would need a flux like in the assay, and higher temperatures as in a furnace. Taking weights and careful notes you should be able to come up with what works best for a process.

 

[nh6886]

Fantastic!
I have about 5 grams of finger foils from AP.
I will do this over the weekend and post my results. I may finally have something to give back in a small way.
Thank you,
John

 

[nh6886]

Deano

Just a quick note I was doing some reading this morning and saw this bit on lead refining and thought of your post. Here's the link if you want to give it a look.
http://books.google.com/books?id=0m-JuMpFZPAC&pg=PA200&dq=precious+Metal+refining&hl=en&sa=X&ei=b7bYUN3MAaOiiQK17oH4BQ&ved=0CEkQ6AEwAzgK#v=onepage&q=precious%20Metal%20refining&f=false
It mentions the way that they are refining lead and recoving their PM with the Parkes process and it got me thinking about this thread again so I thought I would share.
By the way I did try adding the gold foils into the bismuth like Butcher mentioned above and it alloyed into the Bi at around 750F. I proved it up with a XRF check of the surface finding the Au not perfectly alloyed but certainly present throughout. I have not cupelled the Bi yet as the Au is less than 1% so I am going to run some black sand through it first to try and add some fines and eliminate the black sand and what I believe to be zircon sand that is better at staying with the Au than I am at panning. I hope to get the Au to at least 5% before cupelation. So now I have to start looking into the next steps. I am going to put the whole experiment into a new post when I get the results.

All the best,
John

 

[ericrm]

do someone knows if one could use molten zinc to alloy gold?

 

[qst42know]

Yes, but with it's own set of problems.

http://en.wikipedia.org/wiki/Parkes_process

 

[Pantherlikher]

I still like Deno's thought process... Lead might be a tad off unless you get wheel weights free...
Tin, lead and silver however, is something that comes from E-waste of any kind. And a by-product of E-waste. Maybe Deno can use his unique hamster wheel and work on refinning Tin and end up with by-products like Lead, Silver, Gold and other worth while metals.

This would help solve his idea if viable as well as solve the Solder "what the hell do we do" with issue.

BS.
Sometimes the mass dissalusional, kaotic mind is the right way to go...
:lol: