# Is there different acid solution for processing kovar (magnetic) gold plated pins from the nonmagnetic gold plated pins?



## realtechedo (Sep 3, 2016)

Thanks for your time and comment to my first question. But, let me ask one last question from you guys, 'after separating kovar (magnetic) pins from the nonmagnetic gold plated pins, will I use a different solutions to process or just the AP solution for both and if there is different ways of processing kovar (magnetic) pins from the nonmagnetic gold plated, please, let me know, thanks...


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## butcher (Sep 3, 2016)

The copper II chloride leach will work for both, the reason to keep them separate is the Kovar is an iron alloy with about 54% iron, 29% nickel, 17% cobalt,and very tiny amounts of carbon, silicon, and manganese.

The copper II chloride you use will now contain these other metals along with the original copper of the starting etch solution, so basically eventually this will no longer be a copper chloride but a copper/iron chloride solution, for this reason, you want to also keep this separate from your pure CuCl2 solutions you wish to reuse on just copper.

Just use the solution you do not plan on using on copper later, if you do this much you will generate large amounts of these so it is not a problem just keep the solutions separated and labeled.


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## realtechedo (Sep 4, 2016)

butcher said:


> The copper II chloride leach will work for both, the reason to keep them separate is the Kovar is an iron alloy with about 54% iron, 29% nickel, 17% cobalt,and very tiny amounts of carbon, silicon, and manganese.
> 
> The copper II chloride you use will now contain these other metals along with the original copper of the starting etch solution, so basically eventually this will no longer be a copper chloride but a copper/iron chloride solution, for this reason, you want to also keep this separate from your pure CuCl2 solutions you wish to reuse on just copper.
> 
> Just use the solution you do not plan on using on copper later, if you do this much you will generate large amounts of these so it is not a problem just keep the solutions separated and labeled.



thanks to your comment @ Butcher, and if I get you right - It means I can use the AP solution on both plated pins, but the AP solution I do not plan to use later will be just fine for only kovar (magnetic) gold plated pin? and usage I can dispose off.....


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## butcher (Sep 4, 2016)

Yes, you can use your used copper II chloride solution on Kovar, where it will basically become an Iron chloride solution (keep it separated from your good copper II chloride solutions). You can reuse the Iron chloride solutions or treat it as waste. For more understanding of the chemistry, or reusing your solutions these may help you get a better understanding.


http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?t=19838
http://goldrefiningforum.com/~goldrefi/phpBB3/download/file.php?id=25049
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?t=20006
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=19816&p=203499&hilit=ferric+chloride#p203499


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## realtechedo (Sep 5, 2016)

butcher said:


> Yes, you can use your used copper II chloride solution on Kovar, where it will basically become an Iron chloride solution (keep it separated from your good copper II chloride solutions). You can reuse the Iron chloride solutions or treat it as waste. For more understanding of the chemistry, or reusing your solutions these may help you get a better understanding.
> 
> 
> http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?t=19838
> ...



Thanks for your last comment @ Butcher, you really good in your explanations. But can you tell what quantity or rather what ml of hcl and h2o2 i can use for gold plated say 500g.


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## butcher (Sep 6, 2016)

We most likely have covered the approximate amounts (I may have before I cannot remember. Using the balanced formula for the reaction you can figure it out, with the periodic table for molar weights...

Many of the common reactions have been covered.

After figuring out the balanced equations, the actual amounts can change with reactions, how you apply them (hot/cold) concentrated or dilute acid on a metal, the amount of water in, or from the reaction and other variables...

For many of the commonly used reactions we most likely have discussed them thoroughly, you should easily find them in a search.
Try also the general reaction list, and the guide to the forum. Try using an author's name in a search with the formula, these should lead you to the answer.


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## realtechedo (Sep 6, 2016)

butcher said:


> We most likely have covered the approximate amounts (I may have before I cannot remember. Using the balanced formula for the reaction you can figure it out, with the periodic table for molar weights...
> 
> Many of the common reactions have been covered.
> 
> ...



thanks @butcher, I will get back to your and I will always want you to be of help..


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## realtechedo (Sep 12, 2016)

realtechedo said:


> butcher said:
> 
> 
> > We most likely have covered the approximate amounts (I may have before I cannot remember. Using the balanced formula for the reaction you can figure it out, with the periodic table for molar weights...
> ...



I really want to appreciate all you guys comments previously, but still wondering on this area, how do I recover my gold from full plated gold pins like the pins recovered from fiber Pentium III CPUs and from other old networking boards I mean they are really full plated, will the AP method works also or if there is a better solution, can anyone throw my highlights on it...


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## Geo (Sep 30, 2016)

Processors and their pins is normally processed directly in aqua regia. It is not an easy refine and takes some practice so start with a small but significant amount of the pins. Make sure that ALL of the metal has dissolved. This is the tricky part. Every last bit of metal has to dissolve. There can not be a tiny bit of solid metal left. Did I mention that all the metal has to be dissolved? Use an excess of nitric acid or nitrate substitute but too excessive. Add the nitric or nitrate slowly and in small increments until you are sure that all metal is dissolved. Be sure to add an excess of HCl at the start of the process. You can't really add too much HCl but you can add too much nitric or nitrate. After a thorough inspection reveals that ALL the metal is dissolved, remove the excess nitric acid with which ever method you are comfortable with. Personally, I use sulfamic acid added to a hot solution very slowly in small increments to avoid a boil over. After the excess nitric is removed, filter the solution and precipitate the gold with what ever precipitant you are comfortable with. If you are using ferrous sulfate (copperas), add twice the weight in copperas than you are expecting in gold. If you use SMB, there will be other metals precipitate out of such a dirty solution so the precipitated gold will not be very clean.


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## Lou (Oct 2, 2016)

Has anyone tried nitric/peroxide boosted sulfuric acid for pin dissolution?


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## 4metals (Oct 2, 2016)

> Has anyone tried nitric/peroxide boosted sulfuric acid for pin dissolution?



Back in the day that mixture was used by electroplaters for bright dipping copper based alloys. It was a fast dissolve so it only stayed in the acid for a few seconds. It did emit plenty of the dreaded red cloud.


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## FrugalRefiner (Oct 2, 2016)

I've seen it mentioned numerous times, but usually it has been Vigorously discouraged, including having threads locked.

Dave


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## 4metals (Oct 2, 2016)

Well I didn't lock the thread!

There must have been another reason for it being locked, although it is aggressive.


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## Barren Realms 007 (Oct 2, 2016)

4metals said:


> Well I didn't lock the thread!
> 
> There must have been another reason for it being locked, although it is aggressive.



It's not locked but maybe it should be before any further discussion on the sbubject raises it's raises it's head.


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## Lou (Oct 2, 2016)

Did some searching and ah, I see. 

Scratch that idea guys. I was thinking that if the nitric were titrated slowly into dilute sulfuric acid with hydrogen peroxide it might be more tolerable fume-wise. I can't say I've tried it on copper or pins but...

I can say it works really well on palladium powder with very little NOx emission during digestion, I had tried it at freechemist's advice.


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