Your take on this method for processing pins

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FiP

Active member
Joined
Jun 15, 2015
Messages
37
Hello to all,

I wanted to experiment a way of processing pins that would save some trouble with base metals.
I tried something and the current result seems OK.
Since it is slightly different i wanted to present it for all to comment and suggest to see if its worthwile, could be improved...

Here is what i did:
Very small experiment (6 or 8 pins)
1st: A bath of 30% hydrogen peroxyde for 1 week with shaking and leaving outside to sunlight in closed clear container.
2nd: emptying the spent Hydrogen peroxyde, allowing time to dry.
3rd: Second bath with copper chloride + fresh Hcl with regular shaking with same storage conditions as above

Results: on the third day (today) i have nice foils (seeing them move in solution show they are not too thin. All pins have lost their foils.
See picture (i've pointed some foils, the remaining are under the pins or in solution).

I don't know if anyone has ever tried this, what problems they have encountered...
To separate pins from foils, i was thinking of keeping them stuck to the bottom by putting a strong magnet on the outside of the container bottom and normal rinsing and filtering.
If you have some ideas if this can work (or not) on a bigger scale (more than 8 pins :lol: ...) please feel free to share.

My best to all
 

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The process looks interesting. You might ask a moderator to change the thread name because texting lingo is against forum rules for safety reasons.
 
Geo said:
The process looks interesting. You might ask a moderator to change the thread name because texting lingo is against forum rules for safety reasons.
Thanks for that.
Will do
 
1st: A bath of 30% hydrogen peroxyde for 1 week with shaking and leaving outside to sunlight in closed clear container.
Besides getting the pins wet and sort of cleaning them, what do you hope to accomplish with this?
 
goldsilverpro said:
1st: A bath of 30% hydrogen peroxyde for 1 week with shaking and leaving outside to sunlight in closed clear container.
Besides getting the pins wet and sort of cleaning them, what do you hope to accomplish with this?
The idea which really was as a small scale test was to corrode the material (did some research on it) so that the acid would leech more easily since the problem for pins is too much base metals. After a week the base metal was strongly corroded (black, a bit coarse, sorry no picture). The gold was untouched. The goal of the 2 step process was to avoid gold to go in solution.
And off course as you said, after a while hydrogen peroxyde will decompose into water, but the high percentage could probably allow for a longer reaction time.

I don't know if the gold flakes came off because of only regular copper chloride and Hcl action or if the prior hydrogen peroxyde helped to lift them. The fast result made me think it had an effect. That's why i'd like to compare with what others have experienced to see whether the Hydrogen peroxyde played a role in it.
Any thoughts?

My bests
 
I've used AP for about four years now and have not had any gold (that I could find later) dissolve. Unless you are adding peroxide continuously, copper(II) chloride doesn't dissolve gold.
 
Geo said:
I've used AP for about four years now and have not had any gold (that I could find later) dissolve. Unless you are adding peroxide continuously, copper(II) chloride doesn't dissolve gold.
Good point you are making. There seem to be no consensus on this. Some say it dissolves and others say the contrary.
I have a spent AP solution and i've put some copper to cement in it so i can test if any gold was lost in the process.

Apart from this point did you ever get flakes off from pins someway? I haven't stumbled on it yet. So i'm asking on the forum to see if the process i described above has any validity or could be done better in a different manner because flakes are easily recovered and processed.

Thanks

My bests
(by the way the title seems to have been edited, thanks for telling me)
 
artart47 said:
Hi !
I am curious! During the week in just H2O2 did the solution change color or was there any sign of a reaction occurring?
artart47

Hello,

During the week there was no color change to the solution. I could observe some tiny fizzy bubbling (O2 probably) on the pins and they blackened over time. At the end of the week. The hydrogen peroxide was nearly all water but it still had very limited reactive strenght.

My bests
 
The advantage of digesting all the pins is that you are left with clean foils. On a big scale I think you will have a hard time separating foils and pins. The magnet could work to a degree, but you will always trap some gold. And not all pins are magnetic.


Jon
 
I haven't researched yet the fact that H2O2 "corrodes" metals but surely [stt]out[/stt] it will be expensive and slower then AP. Values will go in solution only if you exaggerate with the peroxide as Geo's note. If properly used will not dissolve any value.

Marco
 
You can effectively do the same thing with already prepared, or reused, copper (ii) chloride leach. Not with "Acid / Peroxide" in the literal sense. I've done exactly that only weeks ago with one of several small batches of most likely Kovar tabs (wide, flat sort of pins), when I noticed they'd all given up their foils and I tried to shortcut their complete dissolution.

For me, it was the remaining heavy iron-like tabs staying as sediment while swirling then decanting the foils. The tabs stop moving pretty much immediately while the foils continue to "snow dome" for a while. It worked, but I had split the batch. Most foils remain in my decanted leach and a few stay with the tabs (heavy pins).

Then it's a matter of rinse and repeat. Literally. It takes a few additions of water and "snowdoming" to wash all the foils out.
I didn't think of a magnet. That would have helped.

It was then a matter of carefully decanting the leach off its foils and rejoining all the foils.

I share my experience as an example of something to probably best avoid. It's time consuming but it DOES work perfectly.
I agree, that it probably doesn't scale up very well.

Edit: My success was also likely due to the fact that my pins are very flat. Little square/round pins might not fare so well.
 
MarcoP said:
I haven't researched yet the fact that H2O2 "corrodes" metals but surely [stt]out[/stt] it will be expensive and slower then AP. Values will go in solution only if you exaggerate with the peroxide as Geo's note. If properly used will not dissolve any value.

Marco

I found a good few online articles mentioning the "corrosion" effect. If i remember well it was due to the action of the O2. And i think you are right it would be expensive to do it on purpose. I tried it because i have a jar that i started to use and have no other use for it now since i have plenty of copper chloride. The thing is that hydrogen peroxyde doesn't keep very well so i thought of this method as a way of using it before it is wasted, basically. I don' think (at present) using it as a first choice method would be wise economically speaking.

My bests
 
jason_recliner said:
You can effectively do the same thing with already prepared, or reused, copper (ii) chloride leach. Not with "Acid / Peroxide" in the literal sense. I've done exactly that only weeks ago with one of several small batches of most likely Kovar tabs (wide, flat sort of pins), when I noticed they'd all given up their foils and I tried to shortcut their complete dissolution.

For me, it was the remaining heavy iron-like tabs staying as sediment while swirling then decanting the foils. The tabs stop moving pretty much immediately while the foils continue to "snow dome" for a while. It worked, but I had split the batch. Most foils remain in my decanted leach and a few stay with the tabs (heavy pins).

Then it's a matter of rinse and repeat. Literally. It takes a few additions of water and "snowdoming" to wash all the foils out.
I didn't think of a magnet. That would have helped.

It was then a matter of carefully decanting the leach off its foils and rejoining all the foils.

I share my experience as an example of something to probably best avoid. It's time consuming but it DOES work perfectly.
I agree, that it probably doesn't scale up very well.

Edit: My success was also likely due to the fact that my pins are very flat. Little square/round pins might not fare so well.

Thank you very much for this!
That's exactly the type of information i was looking for! It's helpful to know you had foils floating around without the use of hydrogen peroxyde.
It seems that this process would be interesting then only if the pins are totally digested for easier processing.

I just looked at my pins and from yesterday's picture they are now half eaten up. Since i dealt with tiny sample quantities i'll leave them in solution untill they are completely digested for record sake. (note that the weather here is still warm and sunny). I'll keep you all posted.

My bests
 
Foils floating off a copper base is just the regular "AP" copper (ii) chloride process - poorly named as it is. The leach permeates the gold and attacks the underlying base metal. It's been covered half a million times.

Simplistically, copper solution begets copper solution, assuming enough free acid. Think of it like a sourdough bread "mother", my credit to Pantherlikher for that tip. I haven't added new peroxide to anything for over a year.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=8670&p=214923&hilit=artsy+stores+beer+glass+peroxide+once#p214923

If you add peroxide, you HAVE to dissolve all your base metal. Otherwise any prematurely dissolved gold could be cemented powder and you can lose it.

Now in my case, with assumed Kovar pins, the more green-tea than emerald colour is consistent with my leach heading more towards something ferrous than cupric. It kind of ruins the leach, at least in my experience.

If you have a very large volume of pins, there are better ways to handle it than leaching. The sulphuric cell is more efficient and creates less waste. It is also a less forgiving chemical than chloride leach. Personally I have not had great success yet gaining concentrated H2SO4 so I have stick to slow leaching. YMMV.
 
Hello to all,

Just a quick update:
Today the pins are completely gone.
The foils are intact.
No powder or sediments at the bottom.
Solution color is a mix of emerald and ferric (black brownish) like before but darker.

My bests
 
That colour is characteristic. If you were to add oxygen, through a fish bubbler, you'd likely find it turn green again.
As long as there is any undissolved base metal, that metal will keep using up the free CuCl2 and keeping your solution dark.
So my recent take on this is that it's only after it finally turns green - and is oxygenating again - that you can be really sure all base metal is dissolved.
 
jason_recliner said:
That colour is characteristic. If you were to add oxygen, through a fish bubbler, you'd likely find it turn green again.
As long as there is any undissolved base metal, that metal will keep using up the free CuCl2 and keeping your solution dark.
So my recent take on this is that it's only after it finally turns green - and is oxygenating again - that you can be really sure all base metal is dissolved.

Thanks for that
I'm not so sure about this aspect since i have cemented some solutions and with copper tubing in them they went completely clear (see through green), and when i took it out it went dark again... Maybe it has something to do with exposure to light?

My bests
 
When using HCl and H2O2 to form a copper II chloride leech (AP), if you use H2O2 greater than the 3% strength, the chance of dissolving gold increases. The higher the strength of the H2O2, the higher will be the chance of gold dissolving. Using the 3% found in most grocery stores, WalMarts, etc., should be fine. Also remember that you only need a tiny amount to get the reaction started. I'm pretty sure I have read where some people have used a gallon of HCl and 1/2 gallon of H2O2. THAT'S WAY TOO MUCH H2O2! For a gallon of HCl, a cup of H2O2 is plenty. Even less will do. Also, you will not cement copper out of a copper II chloride solution by using copper. All you will manage to do is dissolve the copper you were trying to cement the original copper in the solution to. You cement out the copper in solution by using scrap steel. I have successfully used angle iron, but others on the forum recommend using old transformer laminations.
 
bswartzwelder said:
When using HCl and H2O2 to form a copper II chloride leech (AP), if you use H2O2 greater than the 3% strength, the chance of dissolving gold increases. The higher the strength of the H2O2, the higher will be the chance of gold dissolving. Using the 3% found in most grocery stores, WalMarts, etc., should be fine. Also remember that you only need a tiny amount to get the reaction started. I'm pretty sure I have read where some people have used a gallon of HCl and 1/2 gallon of H2O2. THAT'S WAY TOO MUCH H2O2! For a gallon of HCl, a cup of H2O2 is plenty. Even less will do. Also, you will not cement copper out of a copper II chloride solution by using copper. All you will manage to do is dissolve the copper you were trying to cement the original copper in the solution to. You cement out the copper in solution by using scrap steel. I have successfully used angle iron, but others on the forum recommend using old transformer laminations.

Thank you for this answer.
As i was discussing with Geo that's the problem with AP some say you can dissolve gold some say you can't...
That's why i tried to cement gold out of an old AP solution giving it copper and i got black cementation around it which i haven't recovered and tested yet (to see whether it's gold or not). (But i've cemented gold successfully with copper before out of a nitrate solution, unless i'm mistaken it looks that chemistry should be the same).
I was previously answering a post about the possibility of losing gold in a powdered sediment form if the solution doesn't go clear. I just shared what i have seen (i'm much less experienced though). I found it interesting that when i took out my copper out of the AP waste solution (that i was trying to cement to see if any lost gold would show up) the solution got dark again when the solid copper was removed. You could see through it before, it just had a light green color and once the copper was removed, it went black (meaning you can't see through it but if you look at drops, it's still green though). This for me showed that copper chloride solution going clear is not necessarily a sign that all base metals are dissolved.
By the way i still have some of that solution in 2 different vessels (one dark where the solid copper copper was removed and one clear where the solid copper remained and a small amount of hcl was added to create fresh copper chloride leaching solutions which i've used succefully so the volume left is reduced).
Indeed chemistry has its mysteries but being curious and investigating (safely off course) makes it really interesting and enjoyable. I'm really intrigued by this color change my thinking goes towards some interaction with light that is prevented when solid copper is in solution, but it's only a gut so if anybody knows more, that would be interesting to hear.

As regards the process i was trying, the pins completely dissolved in copper chloride in 3 days in warm (not hot) weather. The pins where the type you find on the power supply for HDD, they came out an old power pc mac, i tried these because they were the bigger i had on my hands at the time i initiated this small experiment.
Anybody feels it improved speed (one week in hydrogen peroxyde 30% and then 3 days in copper chloride + fresh HCl)? Or it's just normal (3 days then).
I'm getting a batch of pins ready at present, i'm still wondering whether i will do it the regular chemical way (CuCl) or try this method again weighing, timing and all... To keep moving forward while i'm working on my cell.

Thank you to all for your feedback, help and interest.
My best to all and to you bswartzwelder off course
 
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