recovering dissolved gold in AP solution
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I can't say about peroxide to HCl/Bleach mix, It really should not be neccessary.
HCl/Bleach will dissolve gold powders or foils and even PGM powders by itself.
HCl/Peroxide will dissolve same, but none of these methods are well suited for solid metals.
The HCl/bleach mix has to be watced more closely so one don't add too much Bleach,
since it will neutralize the HCl.
Not so much a problem with HCl/Peroxide.
I can't say about peroxide to HCl/Bleach mix, It really should not be neccessary.
HCl/Bleach will dissolve gold powders or foils and even PGM powders by itself.
HCl/Peroxide will dissolve same, but none of these methods are well suited for solid metals.
The HCl/bleach mix has to be watced more closely so one don't add too much Bleach,
since it will neutralize the HCl.
Not so much a problem with HCl/Peroxide.
I realise this is an old post but I made the same mistake. I believe I added to much peroxide to my AP solution. The gold foil that was on the chips has come off, but I am not seeing any solid foils in the liquid. I think it has gone into solution. What is the best method of recovering the dissolved gold foils from my AP solution? Thanks.
If you have any more edges to strip simply add them to your solution, as the copper dissolved any dissolved gold will cement back out of solution, it will look like black powder and not gold.
Also make sure all the metals have dissolved from the chips as if any is left your gold could have cemented back out onto it.
Also make sure all the metals have dissolved from the chips as if any is left your gold could have cemented back out onto it.
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firespot said:
You probably havent dissolved the gold. You've possibly plated the gold with Tin from the solder on the components. It's there but under the Tin.
This whole "dissolving gold in AP thing" has become one of these urban myths that grows in stature with each passing year. Yes it's technically possible to dissolve gold with too much peroxide BUT the reality of the situation is that it both extremely rare, and it will all precipitate out back onto the base metals you are exposing by doing so. It does so as dark/black powder.
IF you're in a situation where you think you used too much peroxide and there are no visible metals then a quick stannous test will reveal all.
In the vast majority of cases it's what I said at the beginning- Tin plating back over your gold. Hmm maybe that's what lead to this whole thing in the first place...
Regards
Jon
Yggdrasil said:
Since you mentioned that non of these methods are suitable for solid metal...What possibilities do I have to redissolve a gold button in order to refine.. I do not have nitric...the only chemicals I have are household..HCl, bleach, or peroxide 34%. It will take forever. Any one done this before?
If you can thin down the metal providing a larger surface area it will speed things up, so make it as thin as possible.
As Nick says!!
Pound it as thin as you can, cut it in thin stripes and twist it into a spiral like shape.
This will crate the maximum availabe surface comparing to the volume.
And since you have 34% peroxide, I would go for that, in order to avoid neutralizing the solution.
I have used it in several occasions.
Just add a few ml into the HCl and stir, when the bubbling has stopped add a few ml more.
Make sure you have headroom in the vessel to avoid bubbling over.
I have always kept the solution cold (room temperature below 20 deg C).
The speed may increase by increasing the temperature, but the oxidiser (Peroxide or Bleach) will break down/evaporate faster then.
Depending on the amount of metal, it may or may not be important in your case.
Good luck
Pound it as thin as you can, cut it in thin stripes and twist it into a spiral like shape.
This will crate the maximum availabe surface comparing to the volume.
And since you have 34% peroxide, I would go for that, in order to avoid neutralizing the solution.
I have used it in several occasions.
Just add a few ml into the HCl and stir, when the bubbling has stopped add a few ml more.
Make sure you have headroom in the vessel to avoid bubbling over.
I have always kept the solution cold (room temperature below 20 deg C).
The speed may increase by increasing the temperature, but the oxidiser (Peroxide or Bleach) will break down/evaporate faster then.
Depending on the amount of metal, it may or may not be important in your case.
Good luck
Yggdrasil said:As Nick says!!
Pound it as thin as you can, cut it in thin stripes and twist it into a spiral like shape.
This will crate the maximum availabe surface comparing to the volume.
And since you have 34% peroxide, I would go for that, in order to avoid neutralizing the solution.
I have used it in several occasions.
Just add a few ml into the HCl and stir, when the bubbling has stopped add a few ml more.
Make sure you have headroom in the vessel to avoid bubbling over.
I have always kept the solution cold (room temperature below 20 deg C).
The speed may increase by increasing the temperature, but the oxidiser (Peroxide or Bleach) will break down/evaporate faster then.
Depending on the amount of metal, it may or may not be important in your case.
Good luck
Yeah I bubbled up a couple of times
) I know how that feels :lol: :lol: :lol:anachronism said:
After straining the fingers from the AP, they were clean, no sign of any gold or tin on the fingers where there was a bunch before. Only explination is, the AP solution reacted with the city water that I used to rinse the fingers...DUHHHHH!!!!!
I don't use a ratio. I add the hydrochloric, enough to cover the material well with a small bit of water and heat it to moderate heat(medium mark on my hotplate). Then I add the nitrate, usually a sodium nitrate for me, in small quantities. It will take some minutes for it to react, adding a tiny bit of sulfuric acid will speed it up if available. Once it starts allow it to react until it completely stops then add more nitrate.
For example, judging by the size of beads in your picture, I would place them in a 100ml beaker, add about 20ml hydrochloric, about 5ml of water, heat it up, then add maybe 1/8 of a teaspoon of nitrates. Allow it to fully stop reacting, and add more based on the amount of material I had left over. Afterwards it is standard filtering and washing.
If you have a gram of sodium nitrate, the amount of available nitric will be slightly less than a gram potassium nitrate will provide. Working with a small amount, and with in reason, there is no noticeable difference in them. There is a way to calculate the exact amount but I haven't done it for many years. Geo, butcher and a few others might can help with exact numbers better than I can.
For example, judging by the size of beads in your picture, I would place them in a 100ml beaker, add about 20ml hydrochloric, about 5ml of water, heat it up, then add maybe 1/8 of a teaspoon of nitrates. Allow it to fully stop reacting, and add more based on the amount of material I had left over. Afterwards it is standard filtering and washing.
If you have a gram of sodium nitrate, the amount of available nitric will be slightly less than a gram potassium nitrate will provide. Working with a small amount, and with in reason, there is no noticeable difference in them. There is a way to calculate the exact amount but I haven't done it for many years. Geo, butcher and a few others might can help with exact numbers better than I can.
