# major problem need advice



## socorban (Mar 10, 2007)

Ohhh man, i was jsut smelting and the cupel broke, all the contents poured out onto and aluminum base plate i had on the work bench, there was at least 2 or 3 grams in the cupel and it fused to the aluminum in a shell of borax, i tried to scrape some of the aluminum off and resmelt it in another cupel but it seems the aluminum wont release the gold, i cant see it anywhere in there.

I put a bunch of borax in there, meltied it and dumped the excess of ina beaker with water and sulfuric acid trying to clean the now balck borax, i repeated several times but the gold is no where to be found  

Anyone have any ideas? normally i wouldnt be so upset but there was a nice big glob of gold in there, at least 2 or 3 grams! What do i do??????


----------



## Noxx (Mar 10, 2007)

Hum... this is no good at all. I don't have much idea but maybe you could try puting some nitric acid ? It easily dissolves aluminium and borax but not the gold


----------



## socorban (Mar 10, 2007)

yea that was my first idea, i dont have any but i guess it would be a wise investment right about now, im not willing to jsut toss out 2 or 3 grams of gold.


----------



## lazersteve (Mar 10, 2007)

Socorban, 





HCl will eat Al for lunch in no time flat. This is a very violent reaction so do small amounts of the Al sheet at a time so as not to generate a lot of heat and bubbles. Do a few tests with some plain Al foil so you know what to expect.




You can even dilute the HCl with distilled H2O to slow the reaction and absorb the heat, try 3 H2O to 1 HCl.
Once the Al is gone just process the borax/gold like it was part of a batch in a cupel.

Good Luck,

Steve


----------



## Noxx (Mar 10, 2007)

Yes HCl will work marvelously if you don't have nitric acid. Stay tuned for my tutorial tonight on how to make nitric acid.


----------



## Harold_V (Mar 11, 2007)

Noxx said:


> Hum... this is no good at all. I don't have much idea but maybe you could try puting some nitric acid ? It easily dissolves aluminium and borax but not the gold



Nope! 

Nitric will *not* dissolve aluminum, but HCL will, and with gusto! So will sodium hydroxide, but each of them can do so violently, so work cautiously.

HCL is considerably safer to use, and readily and inexpensively available at hardware stores by the name muriatic acid. The fumes are horrible----so a fume hood is a great idea--or work with the wind at your back or side.

Harold


----------



## Noxx (Mar 11, 2007)

Sorry !  
I taught it could dissolve aluminium.


----------



## Harold_V (Mar 11, 2007)

lazersteve said:


> You can even dilute the HCl with distilled H2O to slow the reaction and absorb the heat, try 3 H2O to 1 HCl.



In this instance, there's no need for distilled water. Tap water would serve equally as well. 

Harold


----------



## socorban (Mar 11, 2007)

OK, so im going for muratic acid. Will it disolve the gold as well?
My problem is that the aluminum, the gold, and the flux are all together now, i shoulda consulted you guys right afte rit happend but i was hasty and tried scraping most of the aluminum off and melting it down trying to get it apart, now its all one :? so i beefed big time. And im not using aluminum as a bench heat gard anymore, im goin to use tile which a friend recomended.

Would an Ace hardware have muratic acid? What is it general use for so i know were to look in hardware stores.


----------



## Noxx (Mar 11, 2007)

HCl won't dissolve gold.
I think Muriatic Acid is used for cleaning cement.


----------



## Harold_V (Mar 11, 2007)

socorban said:


> OK, so im going for muratic acid. Will it disolve the gold as well?



No----in fact, in the presence of aluminum, gold won't go into solution, and if it happens to on a limited basis, the aluminum will precipitate it instantly as a fine powder, likely black or purple in color. Remember the electromotive series posted by Steve. 



> My problem is that the aluminum, the gold, and the flux are all together now



All is not lost. Regardless of what you do to your gold, as long as you don't toss anything, you haven't lost it. You'll learn as you progress that nothing should be discarded until you know it's valueless. If you get in the full swing of refining, and handle bench wastes, even the saw blades that jewelers toss in their sweeps end up in your "stock pot"----where minute traces of gold are recovered eventually, and the blade acts to precipitate traces of values from solutions that won't allow precipitation. A good example of that would be a batch of jewelers waste, where the benchman has worked a little platinum. Platinum, in solution, is precipitated with ammonium chloride, but it has a quirk whereby it won't precipitate when it's dilute, and typically won't precipitate completely. You recover the traces by placing your solution in a "stock pot" that has scrap steel in it. You end up with some ugly sludge in the bottom of the plastic container, and the steel eventually disappears. The sludge can be processed chemically to further recover the concentrated values, or it can be run in a furnace for reduction, which was my procedure. You'd be surprised at the amount of value that accumulates over time. 



> And im not using aluminum as a bench heat gard anymore, im goin to use tile which a friend recomended.



Those of us that refine, or have done so, have problems that are not peculiar to most other hobbies. For one, we use considerable heat, plus we work with chemicals that are damaging. You will eventually start thinking in such a way that your little accidents don't cost you. My "come to Jesus" meeting occurred the day I was handling 5 ounces of molten gold and dumped it on my counter, which, luckily, was covered with a sheet of Transite (asbestos board). The majority of the gold stayed on the asbestos, but over two ounces hit the concrete floor, molten. The entire area was well cleaned and the processed, but about a quarter ounce of gold was lost, likely in tiny cracks and other crevices from which it couldn't be extracted. From that I learned my lesson. Don't work without a catch basin. I made a rectangular box of Transite that was deep enough to contain any possible spills, plus it was used when melting pure gold. It has a way of tossing off miniscule balls as it coalesces, so by using the container when I'd melt my double refined gold, it was fully recovered. 



> Would an Ace hardware have muratic acid? What is it general use for so i know were to look in hardware stores.



Muriatic is generally readily available at Home Depot----and as Noxx suggests, it's used for washing or etching concrete or masonry projects. Brick is washed with muriatic to remove unwanted mortar. Paint stores that sell epoxy kits for concrete might even have it. Buy the unbuffered stuff, which is slightly off clear in color. It it's dark, it's buffered. Could be it would work as well, but it also may have contaminants that would not be in your best interest. I never used the buffered type, always bought HCL in 55 gallon barrels from the chemical supply house. 

If you'd like my advice, and please feel free to disregard anything I have to say here------

Start the process by dissolving any and everything that will go into solution with HCL (muriatic). Don't toss solutions------decant them and take them up with at least one volume of water, then allow them to sit until they are clear of any particulate matter, especially if you see a purple color. That's likely colloidal gold. You may end up with a lump of gold that is still alloyed with aluminum. If so, you'll have to melt it with something that will allow the HCL to break it down. I'd suggest using zinc, which you'd do by melting the lump first, then introducing the zinc. You'd have to get the gold down to less than 25% for this to work. Stir the lot and then pour it into a deep metallic tub of water. A 5 gallon steel pail would be marginal for the purpose. Something deeper would be better, so the alloy doesn't have a chance of soldering to the bottom. The idea here is to turn the lot into thin wafers (sort of like corn flakes), which will happen when it's poured in water. Pour slowly, so the stream is thin and move around the container so you don't concentrate it in one spot. Recover the wafers and go after them once again with HCL. Save anything that doesn't dissolve-----even earthen stuff. When you have everything dissolved, the residue can then be processed with AR to recover the gold. 

Harold


----------

