Gold plated pins from cpus
- Thread starter Rreyes097
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Yeah, that's what I normally do. But I was hoping to just do aqua regia
Martijn
Well-known member
Trash in, trash out.
Recover first, then refine.
I would go the AP route.
Recover first, then refine.
I would go the AP route.
Really? Why is that? Trash? Why do you say that? Please expand on that. I don't feel it's trash, not grade A material but it's uniform at least. But you do know your stuff so I'm inclined to believe you martijn.
glorycloud
Well-known member
I believe that the "trash" being referred to is the tin and not your gold pins.
Using HCL first to eliminate the tin will help to when you use AR later.
Using HCL first to eliminate the tin will help to when you use AR later.
Martijn
Well-known member
It's a phrase like 'when in doubt cement it out' to make people think about taking shortcuts and skipping steps in a process.
Actually, that's where you (could) learn the most from. Making small mistakes.
If you fry an egg in a dirty pan you could be eating anything. Where has that pan been? the toilet? Hence the ??? In the equation.
Work clean. Follow steps and procedures to the tee.
If you want pure gold (the whole purpose of this forum) anything that's not gold is in fact trash. Possibly very valuable trash, but still trash.
Actually, that's where you (could) learn the most from. Making small mistakes.
If you fry an egg in a dirty pan you could be eating anything. Where has that pan been? the toilet? Hence the ??? In the equation.
Work clean. Follow steps and procedures to the tee.
If you want pure gold (the whole purpose of this forum) anything that's not gold is in fact trash. Possibly very valuable trash, but still trash.
Martijn
Well-known member
And AR is a refining step which indeed has been discouraged here many times to use on pins.
You can get rid of the trash (base metals) without changing the state of the gold. You can then even clean the gold foils further without any gold going in solution. More trash gone.
Or you could get the gold from the trash in a sulfuric stripping cell or with cyanide. Many options. I would take the AP route. Silly me.
These are called recovery steps.
Refining is done with e.g. AR. Where gold is dissolved to separate from the last bits of trash: pgm's, plastic, any organics or sand etc..
The last bit of trash is dealed with in the washing your powder steps. After that you have nearly pure gold.
Not meant to hurt any feelings my dear friends. Love you all.
You can get rid of the trash (base metals) without changing the state of the gold. You can then even clean the gold foils further without any gold going in solution. More trash gone.
Or you could get the gold from the trash in a sulfuric stripping cell or with cyanide. Many options. I would take the AP route. Silly me.
These are called recovery steps.
Refining is done with e.g. AR. Where gold is dissolved to separate from the last bits of trash: pgm's, plastic, any organics or sand etc..
The last bit of trash is dealed with in the washing your powder steps. After that you have nearly pure gold.
Not meant to hurt any feelings my dear friends. Love you all.
This depends mostly on your expectations.
Putting pins straight to AR is my routine. But my pins runs typically about 10g/kg. With heavy plating, processing with AP is often slow as the acid have hard time to get under the gold many times. And I don´t want to spend hour with beating the pins with hammer, bending them with pliers or cutting them with snips just to speed this up.
I just cannot have three buckets full of HCl/copper solution with air bubbler running in my lab for few weeks. In my home, also impossible. So I personally need to do it quickly.
With higher gold content, precipitating values from dirty solution is always easier. Gold settle more quickly. So my sacrifice/toll to this is 800ml-1L of nitric for every kilo of pins. Which could be totally replaced by oxygen in the long run in AP.
With low yielding material, processing can become frustrating, as fine sediment of gold often settle slowly etc... I have also done low yield material with straight AR, but then I advise to use suitable flocculant for easier manipulation with gold. I have gone as low as 1,5g/kg... It can be done=that does not mean it is a good way.
In the end, you get fairly dirty gold. Either second refine or carefully wash few times with boiling HCl and hot ammonia.
As it was suggested here, quick boil with HCL can help you remove tin from the pins before AR. Avoiding some precipitate difficult to filter later on.
Personally I didn´t have some big problems arising from tin in AR. It goes slower when filtering, but it it still go.
Putting pins straight to AR is my routine. But my pins runs typically about 10g/kg. With heavy plating, processing with AP is often slow as the acid have hard time to get under the gold many times. And I don´t want to spend hour with beating the pins with hammer, bending them with pliers or cutting them with snips just to speed this up.
I just cannot have three buckets full of HCl/copper solution with air bubbler running in my lab for few weeks. In my home, also impossible. So I personally need to do it quickly.
With higher gold content, precipitating values from dirty solution is always easier. Gold settle more quickly. So my sacrifice/toll to this is 800ml-1L of nitric for every kilo of pins. Which could be totally replaced by oxygen in the long run in AP.
With low yielding material, processing can become frustrating, as fine sediment of gold often settle slowly etc... I have also done low yield material with straight AR, but then I advise to use suitable flocculant for easier manipulation with gold. I have gone as low as 1,5g/kg... It can be done=that does not mean it is a good way.
In the end, you get fairly dirty gold. Either second refine or carefully wash few times with boiling HCl and hot ammonia.
As it was suggested here, quick boil with HCL can help you remove tin from the pins before AR. Avoiding some precipitate difficult to filter later on.
Personally I didn´t have some big problems arising from tin in AR. It goes slower when filtering, but it it still go.
No hurt feelings here. I told you I know that you know your stuff and I still haven't learned nearly anything. But I'm running into a clumping problem. I've done roughly 2 batches via AP and every time it clumps. I know I could come stir it each day but it's in there for so long I forget about it. Despite many rinses I still feel like I'm missing gold. That's why I was curious. I'll just continue with the AP.And AR is a refining step which indeed has been discouraged here many times to use on pins.
You can get rid of the trash (base metals) without changing the state of the gold. You can then even clean the gold foils further without any gold going in solution. More trash gone.
Or you could get the gold from the trash in a sulfuric stripping cell or with cyanide. Many options. I would take the AP route. Silly me.
These are called recovery steps.
Refining is done with e.g. AR. Where gold is dissolved to separate from the last bits of trash: pgm's, plastic, any organics or sand etc..
The last bit of trash is dealed with in the washing your powder steps. After that you have nearly pure gold.
Not meant to hurt any feelings my dear friends. Love you all.
Martijn
Well-known member
Some more advice from a hobbyist:
Is there any insoluble cuprous chloride forming clumping the lot together?
If so add a bit of HCL and wait.
If the batch is clumping together from brown precipitate, you may have too much iron or more reactive metal in there cementing out your copper.
Are the pins in some form of strainer in the AP? That way you can lift the whole batch out and shake/rinse the pins clean. Works great to get them loose. I have a plastic pot with tiny holes (1mm holes) inside a perforated bucket (3mm holes) inside a bucket to lift and flush the foils down in the bottom bucket.
Can you desribe what the clump looks like? Or take a picture.
AP is indeed very slow. Not for very large volumes in a workshop with limited space.
A sulfuric stripping cell would do a faster job, but needs almost constant attention.
And at 10gr/kilo yield for the pins, like Orvi's gold mine, (yeah I'm jealous) nitric may be a viable choice if you can still get a profit and deal with all that waste.
To put them straight in AR, is something I would not do, it just doesn't feel right.
All personal preferences I guess.
My AP pin bathces sometimes clump together but i just leave it in and the AP turns back green after some time. Indicating the digestion of copper was faster than the conversion of cuprous to cupric, but still enough free HCL left to convert.
Martijn.
Is there any insoluble cuprous chloride forming clumping the lot together?
If so add a bit of HCL and wait.
If the batch is clumping together from brown precipitate, you may have too much iron or more reactive metal in there cementing out your copper.
Are the pins in some form of strainer in the AP? That way you can lift the whole batch out and shake/rinse the pins clean. Works great to get them loose. I have a plastic pot with tiny holes (1mm holes) inside a perforated bucket (3mm holes) inside a bucket to lift and flush the foils down in the bottom bucket.
Can you desribe what the clump looks like? Or take a picture.
AP is indeed very slow. Not for very large volumes in a workshop with limited space.
A sulfuric stripping cell would do a faster job, but needs almost constant attention.
And at 10gr/kilo yield for the pins, like Orvi's gold mine, (yeah I'm jealous
) nitric may be a viable choice if you can still get a profit and deal with all that waste.To put them straight in AR, is something I would not do, it just doesn't feel right.
All personal preferences I guess.
My AP pin bathces sometimes clump together but i just leave it in and the AP turns back green after some time. Indicating the digestion of copper was faster than the conversion of cuprous to cupric, but still enough free HCL left to convert.
Martijn.
Martijn
Well-known member
Oh, and i dissolve everything.
I dont rinse the half digested pins to get the gold. Foils and dust is all that's left on the bottom. Among plastic leftovers.
The plastic connectors and ram fingers are left in the strainer to rinse clean and discard.
Some plastic connectors still have gold foils in them, they are added to an AR bath after all the goils are dissolved to make sure/check if all free nitric is used up.
Martijn.
I dont rinse the half digested pins to get the gold. Foils and dust is all that's left on the bottom. Among plastic leftovers.
The plastic connectors and ram fingers are left in the strainer to rinse clean and discard.
Some plastic connectors still have gold foils in them, they are added to an AR bath after all the goils are dissolved to make sure/check if all free nitric is used up.
Martijn.
