Looking for advice to refine some gold for the first time

Hi everyone! As some of you read in other thread, I’m a newbie in this world, but I’d like to try at least once about refining gold from some scrap (and it’s not for the money, just for the pleasure of doing it), so after learning and investigating I’d like to know what experts like you think about the process I’ll follow. I’d like to point that I’ll be lucky, and I’ll be able to use a more or less well equipped lab for the occasion; a friend of mine works in a high-school and they found interesting the idea, so they’ll borrow the chemistry lab: equipment, some chemicals, a “professional” hood exhaust and so on, the only things missing for now would be sulfamic acid, SMB and a mask.

Before telling all the process, I’d like to ask about using pure Stannous Chloride Dihydrate for the stannous test (they have that in the lab), I read about it but still not quite sure to transform it in a usable test (with hcl? Just heating?).

And now, speaking about what I’m going to do, I have 2 different materials to process; I will do each and after that melt the resulting gold of both.

First what could be considered around 80 ddr2 ram module’s gold fingers already de-soldered. For that, this is the process I’m thinking to do:

• Put the fingers in distilled water and add some nitric, heat and add more nitric as needed until all base metals are dissolved (medium heat). I didn’t say but I won’t be adding huge amounts of nitric, just small amounts of it. Then filter it after it colds.

• Take what is left, and make AR. Like before, I’ll be adding HCL and the nitric after in small doses until it’s dissolved (medium heat). Then filter again after it colds.

• The resulting solution should be the one with the gold in there, so use sulfamic acid to be sure there is no exceed of nitric and after that add SMB to precipitate the gold, filter it once is all precipitated, clean with water few times and ready for melting.

For the second one I bought one Intel Pentium Pro and four R80186, for this this is the process what I’m thinking to do is pretty similar, but:

• Crack the processors in few pieces and like before, do the first step with nitric to get rid of base metals (low~medium heat). Now, even if I filter the solution instead of taking out the ceramics there could be still gold so I’ll put them in AR too.

• Take what is left from the previous point, and put it with HCL and add in small doses the nitric until all the metals are dissolved (low heat). Now, before filtering add some water to dilute it a bit and because after I investigated I saw that there could be some lead in the solution, add a small shot of sulfuric acid to precipitate it and give some time. After that, filter the solution.

• Now there should be just the solution with the dissolved gold, to remove any excess of nitric I’ll add sulfamic acid and once it’s ok, SMB to precipitate the gold and when it’s done, filter it and clean with some distilled water. After that, it should be ready for melting.

I have taken the small BGA chips from the ram too, they should be around 900 of them, if the other two goes good I maybe try to refine the gold in them too, but that will be for a future.

Anyway, thanks for your time and anything you have to say!

PS: I'm sure it's already known, but in the tour post about the commonly used chemicals the source is broken.

There are many ways to get things done, I am only aware of a few. So here is my take on some of it.

First what could be considered around 80 ddr2 ram module’s gold fingers already de-soldered. For that, this is the process I’m thinking to do:

Put the fingers in distilled water and add some nitric, heat and add more nitric as needed until all base metals are dissolved (medium heat). I didn’t say but I won’t be adding huge amounts of nitric, just small amounts of it. Then filter it after it colds.

I prefer hydrochloric for the removal of copper based base metals normally. While nitric should work fine, I have never used it in this way other than for gold filled materials. If I were to try it, I would calculate a rough idea on the amount of nitric needed and start with around 75% of that amount.

Take what is left, and make AR. Like before, I’ll be adding HCL and the nitric after in small doses until it’s dissolved (medium heat). Then filter again after it colds.

I would clean and dry any foils left and thourghly wash with water several times. This will aid in the removal of residual base metals. The less waste in the less waste to clean up later.

The resulting solution should be the one with the gold in there, so use sulfamic acid to be sure there is no exceed of nitric and after that add SMB to precipitate the gold, filter it once is all precipitated, clean with water few times and ready for melting.

I prefer to add the sulfamic before filtering. This way any lead that may be dropped by it's use can be caught in the filter as well. Then I would do the wash cycle(s) and dry the powders. A wash with hot dilute hydrochloric followed by hot boiling water, then I like hot straight hydrochloric followed by hot boiling water. Repeat as needed until the water and the hydrochloric both come out perfectly clear. I prefer to melt powders without the paper. It seems I tend to blow away less material with out the paper being involved.

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I am sure others do it differently and I hope they chime in with how they would do it as well.

Good advice, I'll take in consideration adding something similar to the amount of nitric you mentioned at the beggining and keep adding from there.

Secondly, I didn't mention it but yeah, cleaning what is left was my intention, still a good reminder that a nice cleaning will help later.

And for the last one, I haven't thought about that, but sound pretty nice the idea: that way the excess will create sulfuric and the filtering will remove lead. In the case of the processors I'll be adding a bit by myself, but still good one For the washing, I wasn't sure about that last cleaning with hydrochloric, but you are not the first one I saw doing it so I think I'll do it.

Thanks a lot for sharing your experience, it will help me in my little adventure.

Long time no see, pals!

I have been a bit busy with work and trying to learn a bit more when I had some time. Probably in few weeks I'll try to refine the gold and see if I can get some. As mentioned before, I'll use a bit "pro" equipment and even a couple of friends of the high-school of the department of chemistry are interested in the process I'll do, they don't know nothing about processing gold but they will be an extra help for safety.

But going to the point, I have a little question about melting the gold powder: I get this torch, with the map-like gas and it's supposed to reach 1600º, but when trying to melt something like a small nugget of copper (the size of a nail, perhaps) while testing it turns red hot but it didn't melt.

Do you think it will work with the gold? It's going to be a much smaller amount of material, I don't expect getting more than 0.9~1g of gold to melt.

As always, thanks for your time and knowledge!

I think you'll struggle with that little torch. The main problem with any torch is that you need to be able to put heat into your material faster than it escapes. Even with larger torches, people have problems unless they insulate their melting dish well. The smaller the torch, the tougher it's going to be. It gets hot enough, but the heat escapes faster than you can put it in. If you can insulate your dish well enough, it might work, but I'd suggest a bigger torch.

Dave

FrugalRefiner said:

I think you'll struggle with that little torch. The main problem with any torch is that you need to be able to put heat into your material faster than it escapes. Even with larger torches, people have problems unless they insulate their melting dish well. The smaller the torch, the tougher it's going to be. It gets hot enough, but the heat escapes faster than you can put it in. If you can insulate your dish well enough, it might work, but I'd suggest a bigger torch.

Dave

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Sadly, after the results, I was expecting something like that... I tried putting a graphite mold I had covering the melting dish (the dish is quite small, trying to avoid that losses). I thought about an oxy-acetylene torch, but the cost would be too much for what I want to spend in this project. Still, gold powder in a small vial would do for me too, so I'll try insulating better in my tests and if I'm not convinced I'll go for that. Thanks for your reply @FrugalRefiner !!

Hello pals, I have something a would like to ask in order to be sure that everything is okay.

We was doing all the experiment, more or less successfully and we had a issue: we dissolved the CPU in AR adding small amounts of nitric, after we finished with that we filtered the solution and added sulfamic acid to neutralise the possible excess of nitric. Until here everything OK.

After that we added Smb to precipitate the gold, and in a moment perhaps we added a bit too much of Smb and it reacted a too much, in that moment even in the venting hood a very strong smell came out (SO2 if I'm not wrong), we close the venting hood door and abandoned the room quickly just in case. The lab windows were opened so after a while we came back.

So, what I would like to know if about if I should worry about that strong smell we had there and we breath for a moment, I want to be sure that everyone is okay and in no risk of nothing. As I said before I... Well, we ended doing for the pleasure of doing and trying and the safety of everyone is the first concern and I want to confirm that.

Yes, that is SO2, it is HCl reacting with SMB and yes, it is bad to inhale and dangerous. It turns into sulfurous acid when mixed with water (like in your body)

If you did the experiment in a suitable fume hood you shouldn't have this problem ?

Warning, it will continue to let off SO2, sometimes for a day or two. My own personal rule of thumb is 2g of SMB for every expected gram of Gold (more than enough)

Yes, it was in a suitable fume hood (or should be... Is the fume hood they have in the high-school's lab) . Thinking about it it maybe smelled that much to me because I was the one who was adding the Smb.

Perhaps I was our fault, as I said earlier, apart from the fume hood we had opened the windows the vent the room, maybe an unexpected air flow (we are having a very hot days too, so it was also to don't concentrate too much temperature in the room) It was something quick, added Smb and I think because of a bit late reaction too much was added and it reacted strongly. It was about 30 seconds or so, in the moment I felt the penetrant smell, leave everything as it was and we abandoned the room.

I had no pain per se, it was more those first minutes being very uncomfortable because of the smell and quite worried about what happened. Just in case I went the the local clinic and explained it, they told me that my lungs looks like working fine (they checked the amount of oxigen in blood and if my throat and my nose was irritated), nothing sounded bad and they told me to check for a while in case I feel tired.

As I said earlier, safety first... I wouldn't mind the end the experiment and lose the gold, we aren't doing it for the gold itself and I value much more my own health, that's why I wanted to explain what happened and how I felt, to be sure that nothing, you cannot be enough paranoid when dealing with those acids and I wanted to know what do you think about ito rif something should be done.

I also do mine in a fume hood too, but yes, sometimes you do get a bit of that smell. It normally makes me sneeze! Sounds like you did all the right things!

You can also use Copperas to precipitate the Gold, it is not quite as bad gas / smell wise.

kernels said:

I also do mine in a fume hood too, but yes, sometimes you do get a bit of that smell. It normally makes me sneeze! Sounds like you did all the right things!

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Thanks... good to know, maybe it was something about having a bit of bad luck: a strong react, some wind and I being perhaps a bit too close, you can never relax with chemicals. I had a nice scare, I always said that safety is my first concern, so in the moment I started smelling that penetrant odor it was like "get the heck out of here", I can't say for sure because everything happened quite fast, but just after breathing and having that disgusting smell was like stop breathing and get out.

Hello again pals!

After almost one week looks like I'm feeling good, so the health seems to be fine (thank god!).

But what I wanted to show is the result of drying what I have gotten:



0'85 grams. I know it is not .999 gold, another AR process should be done but I made all this for fun, so I'm satisfied with what I got and I just wanted to show you.

Felicidades, artista, lo lograstes.

Paco.

Haha, NICE!, great to have something for all that work !