# smelting with aluminum as the flux



## eemtek (Oct 18, 2008)

I heard of a "supposed not to talk about" way of refining boards. It is to make a vat of liquid aluminum and place all the materials to be seperated into the vat. supposedly the lack of oxygen will cause the boards to seperate from the metals with little toxins. Question is how to seperate the preciouse metals from pounds of aluminum. Dont ask me much more on this, I cannot find a patent on it, just know there is a place that does this and makes products for skunkworks.. but they do actually recover the other metals quite easily!


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## butcher (Oct 19, 2008)

my guess is the metals are disolved in acid and aluminum used to precipitate them,very common mining technique, or with smelting them together may be possible, seperation of aluminum and precious metals not that much of problem,check out electromotive series.


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## eemtek (Oct 20, 2008)

thanks for the reply, I do use aluminum for the fast precip. but this is different, it is actual smelting using the aluminum as the flux.. just around 950-1200 deg..


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## butcher (Oct 20, 2008)

interesting, lead or mercury will almagam with gold, why not other metals? I have read in electronics the solder disolves gold (I'm guessing small amounts) 
bismuth mixed with lead will melt as low as 170 degrees F. I wonder if we could use this in our refining? or flux?


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## Platdigger (Oct 20, 2008)

I have heard of it for pm recovery, but there is the danger of any moisture causing the aluminum to blow all over the place.
Just have to be real certain anything introduced to the molten aluminum is completely moisture free.
Never heard of doing whole boards this way tho.
Randy


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## eemtek (Oct 20, 2008)

preheating the boards would be the fix to moisture.. the one post about lead is true to collect gold, lead it a great collector of gold with small amounts of lead needed, but it is toxic and not much fun removing large amounts of lead from gold. I have smelted for fun a load of military canon plugs that i could not seperate to see the results. It did indeed absorb the gold, but even the iron. Only problem is I have found that the aluminum also contained magnesium, so the results are not truely confirmed.. so now I have a 2 pound plate of aluminum and a couple ounces of other metals including gold.. 

thought could be to add just borax and take temp up to 1500... the aluminum should float on top, and the other metals should drop into the borax. possibly skim off the aluminum and take up to 2300 to smelt the rest into a doar bar and then seperate? if anyone tries this, please let me know.. I'm lacking the time lately, so i investigate it in books at night..


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## Platdigger (Oct 20, 2008)

In the "Parks process", zinc is rabbled into molten lead. The zinc having more affinity for precious metals than lead, absorbs them.
Then at a certain temperature the zinc will actually come to the top, were it can be skimmed off, containing the pms.

How, or if this will work with aluminum, I am not sure.

Seems to me, you would have to "load" the aluminum with enough precious metals to make it "worth" separating chemically.
Anyone?
Randy


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## Shecker (Oct 20, 2008)

Aluminum does work as an alternative to zinc in the Parkes Process, but it has a higher affinity for gold and pgm and tends to leave the silver behind.
It is difficult to obtain a clean separation from the lead.

Randy in Gunnison


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## Lou (Oct 20, 2008)

This is an exceptionally bad idea for several reasons:

1.) moisture or even medium high volatility organics on the board can cause a steam explosion. Aluminum is arguable the worst metal (aside from magnesium) to get on one's body. This is because it has high surface tension and is ''sticky''. I would rather spill copper, iron, or whatever on me than aluminum ANY day.

2.) Just because there is no oxygen present does not mean that very poisonous pyrolysis products will not be formed. In fact, it is more dangerous to heat high molecular weight polymers without the presence of oxygen because they can reform into polyaromatic rings which are all carcinogenic. Don't believe me? Look it up. I work in this area. These are very nasty compounds.


Also, aluminum is not a flux in any manner in this situation. It is a collector, and an inferior one at that. It is inferior because its surface tension is high. Lead and zinc are both much more fluid and therefore better encapsulate the values. They also (generally) have higher capacities for precious metals than aluminum not the other way around. See phase diagrams; if you need help reading a phase diagram, ask.

There is no patent on this process because many other processes work much better and with much less hassle. Eemtek, I think this is just a rumor. 

While this process could work, it won't work well without significant efforts put in place. Namely an exhaustive scrubber, doing it in an inert atmosphere, and high temperatures to increase aluminum's ''fluidity''.


Lou


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## Harold_V (Oct 20, 2008)

To add to Lou's comments, if you need a little misery in your life, be certain to include some aluminum in any of your processes. If you manage to dissolve it (it doesn't dissolve in nitric), you'll have a dreadful time filtering the solution. 

Wise people keep aluminum out of their refining processes. 

The only place I used aluminum was to convert silver chloride to elemental silver. I did so because I had the scrap aluminum, and could rinse the resulting cement silver adequately to eliminate the dissolved aluminum. Otherwise I wouldn't have entertained the idea of its use. 

Harold


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## viacin (Oct 21, 2008)

does AR disolve aluminum? I ask because there are about a dozen videos on youtube of idiotic teens mixing AR in hallways and throwing in some aluminum. I've even seen some instructional videos on how to play this "prank". I'm very suprised no one is dead yet.


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## Lou (Oct 21, 2008)

Yes it reacts. Concentrated nitric does not attack aluminum because it passivates the surface.

Hydrochloric acid attacks aluminum, but as Harold mentioned, it is wise to keep it out of refining.

Why? Well, aluminum in solution as Al+3 has this habit of hydrolysis. Aluminum does funny things in aqueous solutions and it will come out of solution as hydrated alumina, or Al(OH)3 at a pH above 1 or so. The OH from waters own autoionization causes this to occur, hence the term ''hydrolysis''. 


Lou


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## eemtek (Nov 9, 2008)

thanks lou for your input.. you are right about as a collector. The toxic rings you talk about are supposed to make a polymer that absorbs rf fields? I got the info from a guy in the state environmental department that was trying to help me. It was a year ago, i actually contacted the company and they have a website that does link to exotic polymers.. Someday i will find it again because i thought it to be off the wall.. The collection of pms was a byproduct, and he said they had no problems removing the pms. I dont think it was chemically, rather electrolitically or by temp? It is being done, for other reasons though.. I just thought it could be a novel way to do it.. Still have not had time to actually go beyond theory. I do have a 2.2 pound aluminum ingot that was one time around 40-50 connectors from an old c130 with 20-40 pins per connector, between 1-2k pins. I dont know why i did it, just maybe bored.. there was an iron core as i remeber, but after dissolving, there was no pms leading me to think the aluminum held it.. just wish i knew the gold value in it.. still rather try other seperation methods than chemical.. lou, you seem knowledgeable about this, would like to discuss more about this.. It might produce toxins, but does it produce less toxins compared to incineration.. could it be less toxins to recover, less kinds of toxins to identify? Im sitting on now 13 tons of boards to work and keeps piling up.. Was doing on the small scale for past few years, but last year lost alot of money and keep finding bad refineries (found 2 dishonest ones in 1 day!).. Get this, i had been seperating lower and med grade boards and selling them off for over $2/lb keeping the high grade. Sent a couple pics off of med to high grade to a refiner in calif and he said he needed a few tons and i should get back between $1 to $1.50 per pound.. Even at $2/lb was low, but i was only selling 500-1000 lbs per month.. Guess high grade boards are not worth as much? Will not deal with them anymore unless i can put an explosive collar around their neck and give them daily lie detector tests.. Pretty much i have decide to give this material up to experiment since i cannot seem to profit from the boards.. If you have any ideas for large scale refining, let me know.. I have tools, machinery, and chemicals for experimenting.. Just dont ask to come visit or help.. I'm good with cyanide, but incineration seems to be the key to make it effectively work.. I'm not into incinerating since there is too many variables to clean up.. its late, hope this makes sense.. night all..


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## Lou (Nov 9, 2008)

I am not anywhere close to the most qualified person here to discourse on recovering from electronics but I can talk to you about a few things.

From a common sense perspective:
As far as incineration goes, you would be better served doing that (from a legal and waste control perspective) than building a large pit furnace. I say this because you get incomplete combustion of those polymers in the boards if you just toss them into a pool of metal, and that's what gives you those nasty polycyclics. Instead, ballmill or grind all the boards to powder, fluidize it with compressed air and inject it into a combustion tower with tangential firing. You'll need a fume scrubber, bag house, and probably frequent output analysis (basically if you smell anything at the end of the scrub process, you're violating the law).


If you're ''okay'' with cyanide, give it a shot--I can talk to you about that because I have used that for low grade materials.

I have plenty of ideas on large scale *refining*, and plenty of things with which I do or plan to do _my_ large scale refining. What you, sir, are doing is ''largish'' scale *recovery*. You're not refining anything, you are reclaiming values.

I think I'll pass on the visit and/or helping--you'd have to pay me really good money to even think about moving, and more to make me consider putting up with the huge hassle of recovering from electronics scrap, especially when your 13 tons of it is just drops in a bathtub (probably still some nice chunks of gold in that 13 tons of boards you have).


Good luck with it,

Lou


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## GeeDub (Feb 21, 2009)

Lou said:


> There is no patent on this process because many other processes work much better and with much less hassle. Eemtek, I think this is just a rumor.



Nope, it's not a rumor. It was used over 30 years ago. Just because you didn't find a patent doesn't mean there wasn't one.


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## goldsilverpro (Feb 21, 2009)

Sure sounds easy, doesn't it. I agree with Harold. Unless you want a lot of grief, keep Aluminum out of the equation,. Been there, done that.


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## eemtek (Feb 22, 2009)

been playing with it on the side, but without a proper seperation plan it is just not profitable.. at least using copper as a collector you can plate out the copper in the end.. the aluminum had a great effect that the small smelter i made for it, slipping the boards under the molten metal, the boards actually broke down safer. they were denied o2 so they released less toxins.. just a process not cost effective. the company that does this process actually does it for the carbon compounds that come out. I can't tell ya what they use it for-> Id have ta kill ya if ya know what i mean 8)


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## goldsilverpro (Feb 23, 2009)

It seems to me that collecting with aluminum is like making silver chloride. They're both easy to do but, what do you do next?


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## eemtek (Feb 24, 2009)

dont you just throw your silver chloride in with a batch of new material with lots of base metals? i do, then just add a sulfuric / oxidizer to remove a load of base metals.. then the silver is restored.. then pick back up with nitric or such.. jd


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