Thomas M Joseph
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Did you do a stannous chloride test?
Accomplished nothing so far
- Thread starter Edwin Price
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Proffshuggarn
I know it’s out there, somewhere..
Answer: ewaste from computers.Hi Edwin
It depends..
Often because you need a ml or two more of nitric (often).
I’m no expert, but some basic questions:
-What are your material? (karat/e-waste etcetera..)
(Edwin, can you be more specific
, the category e-waste could include exactly everything from Asbestos, plastic, tin, solder to palladium and so on.. For examples:-My material is 300g of trimmed RAM-fingers.
-A mix of 25 different ceramic CPU:s.
-3 small trafos, 200g magnetic gold pins with a lot of solder.
-65g concentrate from well Incinerated and pretreated IC-chips. Just examples
)Used HCL, water and heat at first. Then added about 10 ml of nitric 2-3x during the process.
(As a native Swede, I translate that you added already used/reused old contaminated Hcl?
The pro’s (and me too) like to know exactly how much of everything, which grade/concentration, temperatures and what kind of water.. tap water, soda water, distilled water, Muddy Waters
? As earlier said, I’m no expert, but I’ve learned here to use as small amounts of acids as possible, and for making AR, just enough concentrated Hcl to cover the material and let it get a little warm, about 30 degrees Celsius, then start adding ml by ml of nitric and observe the reaction, and to avoid overkill doses)Answer: Yes. The materials were closely trimmed gold/gold plated computer parts. Plastic, tin, copper, fiber board removed as much as possible.
(Edwin, that’s good, but like looking under the water surface, under the gold plating there’s more or less a lot of stuff, depending on exactly what material/components it is, silver is a fine foundation for gold plating, base metals of stainless steel, copper, titanium, brass, nickel, tungsten, solder PGM:s etcetera, and when recovering PM:s from mixed e-waste we have to deal with them in different ways in mostly every batch.
There are no shortcuts, we have to get the plated gold to loose it’s “grip” on what it’s plated on, or dissolve the “gripping” metal underneath on some way, to get the flakes to gliding off. Sorry for my bad English. That’s what I meant when I asked if you had pretreat the material
)Answer: I need to buy some kind of pH meter. Litmus paper is of limited value. My guess is too little nitric. I went from one extreme to the other.
(You got some good advice from the pro’s above, and I think litmus paper is great. And as someone mentioned, our best tool is the stannous test, it takes 30 minutes to produce, just 100ml concentrate Hcl and 13g pure solder-tin, heat for 20 minutes, filter. Search the forum
)Answer: Started with 50% HCL and water solution. HeatedTry to describe the process so exact as you can, then it’s easier for the pro’s (not me) to help you out
(I know, it’s a lot of writing, but you will get more exact answers if you describe your process in detail, and start with small batches of same sort of material, just my tips, you’ll see that your results will rise, and your waste acids will reduce
)/Dennis
Thomas M Joseph
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Yes. As a matter of fact, here’s my latest positive result. That’s only the 2nd time I’ve had a black result. On my first attempts the results were weak purple at best. The last two test batches with way less nitric acid were my first real good results
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Spoons or spotplates are not well suited for Stannous tests.Yes. As a matter of fact, here’s my latest positive result. That’s only the 2nd time I’ve had a black result. On my first attempts the results were weak purple at best. The last two test batches with way less nitric acid were my first real good results
Use a cotton bud or a piece of paper.
Drip a drop of solution on it and then a drop of Stannous next to it and watch the reaction when they meet up.
anachronism
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I'd have to disagree on this Ygg. Ive always used spoons.
I have used both, and especially when things are unclear or unfamiliar, the methods with cotton buds or paper seem to be easier to interpret.
Same when the concentration is high.
anachronism
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Haha when it's high enough to plate out as metal it doesnt matter which you use. Stannous isn't really quantifiable in terms of a good reading as to gold content per litre but if used as its raw indicator as to whether there is gold or not then a solid white background is good enough.
If you are looking for a tiny shade change from white then that solution is probably better served being in your stock pot.
If you are looking for a tiny shade change from white then that solution is probably better served being in your stock pot.
Proffshuggarn
I know it’s out there, somewhere..
Hi Edwin
It’s fun to see when things going forward step by step
. The reason why I prefer litmus paper is that it’s simple, cheap and I can have it in my pocket.
A few years ago I had one of those cheap plastic yellow kina ph-meter “stick”, and I don’t remember what acid i was dipping it into, but the plastic did melt and the meter died
/Dennis
Test run #4 = strong black Stannous indication. I’ve gotten 3 out of 4 excellent positive results for gold so far.
ugh! That’s pretty bad. Mine is definitely cheap plastic.Hi Edwin
It’s fun to see when things going forward step by step
The reason why I prefer litmus paper is that it’s simple, cheap and I can have it in my pocket.
A few years ago I had one of those cheap plastic yellow kina ph-meter “stick”, and I don’t remember what acid i was dipping it into, but the plastic did melt and the meter died
/Dennis
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pH test paper is inexpensive and pretty reliable. You can pick some up on Amazon or eBay for just a few dollars.
Dave
Dave
I will admit I never read this thread because I have no idea what it is about. And now we have 5 pages of a thread which, if searching for a specific topic, the title of the thread gives no assistance. I am not trying to shut this thread down so don't take this the wrong way but, in future threads please choose a topic that can assist future readers in searching for what they are looking for.
For all I know this thread may be about the secret to long life and I'll never know. So please, in the future be more specific in naming threads.
For all I know this thread may be about the secret to long life and I'll never know. So please, in the future be more specific in naming threads.
Martijn
Well-known member
It could be called: 'lots of subjects for the learning curve of a beginning refiner'
It's Edwin's personal guidance thread.
The first reply from spaceship nailed it imo.
JDT
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Hi Edwin, I didn't read the whole thread, but I agree with what I did read. The amount of Ewaste you're processing won't yield enough gold for you to see and learn the reactions. I too struggled to learn with Ewaste. Solution for me was to process 2-3 grams of 10k or 14k scrap gold. It showed me what should happen, and at each stage. And with 3 grams of karat gold scrap, you will yield 1 gram or more of purified high karat gold. Repeat the process for better purity.
Also, make sure the free floating nitric is used up and gone before precipitation, use Urea if needed, add it until fizzing stops. If any nitric remains, it will continue to re-dissolve you're gold even as you add your SMB. I sometimes use large gold pieces to eat up the remaining nitric. And when the reaction stops, I know the nitric is gone.
I use Poormans AR with a 3 parts hcl (100ml) to 1 part sodium nitrate (33ml water with 2grams Sodium Nitrate) ratio. Then I filter when golds dissolved in solution. After filtering I add Urea as needed. Then I drop my gold with SMB.
Good karat gold scrap is great for beginners to see the reaction and understand what it looks like. You can master the chemistry on paper, but until you've had success, you've still have much to learn.
Great news though. Once you've had success and understand everything that happened step by step, it become quite easy. Just don't become complacent. When you're to comfortable, accidents happen.
Bottom line, use less accids with the same ratio, just reduced, and try it again with a good gold source. You'll learn a great deal and understand why ewaste only produces 0.1-0.05 grams sometimes.
Hope I didn't step on anyone's toes or steer you wrong. I only wish you safety and success. Good luck!
Also, make sure the free floating nitric is used up and gone before precipitation, use Urea if needed, add it until fizzing stops. If any nitric remains, it will continue to re-dissolve you're gold even as you add your SMB. I sometimes use large gold pieces to eat up the remaining nitric. And when the reaction stops, I know the nitric is gone.
I use Poormans AR with a 3 parts hcl (100ml) to 1 part sodium nitrate (33ml water with 2grams Sodium Nitrate) ratio. Then I filter when golds dissolved in solution. After filtering I add Urea as needed. Then I drop my gold with SMB.
Good karat gold scrap is great for beginners to see the reaction and understand what it looks like. You can master the chemistry on paper, but until you've had success, you've still have much to learn.
Great news though. Once you've had success and understand everything that happened step by step, it become quite easy. Just don't become complacent. When you're to comfortable, accidents happen.
Bottom line, use less accids with the same ratio, just reduced, and try it again with a good gold source. You'll learn a great deal and understand why ewaste only produces 0.1-0.05 grams sometimes.
Hope I didn't step on anyone's toes or steer you wrong. I only wish you safety and success. Good luck!
Martijn
Well-known member
We have been trying to convince people to stop using Urea for deNOxing.
It is ineffective, rises pH and can under some condition create explosive compounds.
The recommendations are in priority order.
1. Do not use more Nitric than needed.
2. Deplete the Nitric with sacrificial metal.
3. Sulfamic acid.
4. Cement the PMs
Order depends on the preferences of the processor.
Urea belongs in your garden.
Thanks very much! I appreciate the info and advice. I do have some gold nuggets to work with.
For info: I've greatly reduced usage of nitric acid and I have sulphalmic acid now. ty
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I have a lot of questions right now. I appreciate any advice, instructions or confirmation of my plans. I’m at the point on a 300 ml test batch that’s positive for gold that I need to de-nox with sulphamic acid. Approximately how much should I use? How much water should I add to the solution? And, should I shoot for ph of 2-4? IF successful, I’ve got Ferrous Sulphate to drop gold. How long should I wait before adding the FeSO4? I’m anticipating < 0.5g gold. How much Ferrous should I add to drop that small amount? IF I get a successful gold drop should I decant or siphon before washing? Thanks very much for any help. 
