# Hydrogen Peroxide



## Buzz (Oct 16, 2007)

Hi Folks,

I'm going to process a batch of fingers in AP as in Steves video.
The peroxide i have is 6% and i believe Steve uses 3%?

Can i use standard water to dilute or would distilled be required?
Could i just use 6% on its own?

Thanks in advance

Regards
Buzz


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## lazersteve (Oct 16, 2007)

Buzz, 

It shouldn't matter either way. You can just add 1/2 the volume of the 6%peroxide if you want to stick to the recipie (i.e.:4 parts HCl to 1 part 6% H2O2 = 2 parts HCl to 1 part 3% H2O2). 

Steve


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## Buzz (Oct 16, 2007)

Hi Steve,

That's great, thanks for the info.

I meant to ask earlier, does it matter if you mix ISA, PCI and AGP fingers together or is it best to process them seperately?

Kind Regards
Buzz


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## lazersteve (Oct 16, 2007)

Buzz,

It really doesn't matter unless you are trying to compile yield data for a particular type of finger. The only other posssible reason to sort them is that some fingers etch slower than others and you will end up with some partially etched fingers in a mixed batch.

Steve


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## Lou (Nov 4, 2007)

I'm sure this has been mentioned before, but if you just do small scale refining and need H2O2, you can get Baquacil (that's the name I believe) Pool Shock from any pool supply house. It's 27.5% H2O2, stabilized. Remember to wear goggles, gloves and old clothes!


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## Noxx (Nov 4, 2007)

Hello Lou,
No, as far as I know, it haven't been mentioned before where to get hydrogen peroxide from that concentration as a commercial product.
Thanks for the input !


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## Lou (Nov 4, 2007)

Glad to make a contribution, I hope to detail some of the things I've done with precious metals. I found out about this forum through another forum (backyardmetalcasting.com) from a new member there, Harold. It seems he is quite prolific here, and I am glad he recommended me to this forum. 

Regards,
Louis


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## Noxx (Nov 4, 2007)

I tried to register a few time to backyardmetalcasting forum but the admin never activate my account lol... I hope he will soon.


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## Lou (Nov 4, 2007)

Yes, it's increasingly hard to get in there. I know both admins there. I can forward them an email from you if you'd like?


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## Noxx (Nov 4, 2007)

Yes please 
Tell em that I have experience in Gold Refining lol.


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## goldsilverpro (Nov 5, 2007)

Very good contribution, Lou, about the peroxide. I've been pushing for stronger H2O2 since I got here. It's always seemed foolish to use 3% (97% water) because the addition of so much water slows the reaction to a crawl. With 27.5%, you only use approx. 1/9 as much water. I have always used 30% or 35% but, 27.5% is close enough. The main problem has been where to get it. Were I to use HCl/H2O2, I would use HCl full strength and a drip system for the strong peroxide, using agitation to constantly balance the peroxide in the solution.

And, small additions of strong H2O2 will jack up most dissolving reactions.


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## Irons (Nov 5, 2007)

goldsilverpro said:


> Very good contribution, Lou, about the peroxide. I've been pushing for stronger H2O2 since I got here. It's always seemed foolish to use 3% (97% water) because the addition of so much water slows the reaction to a crawl. With 27.5%, you only use approx. 1/9 as much water. I have always used 30% or 35% but, 27.5% is close enough. The main problem has been where to get it. Were I to use HCl/H2O2, I would use HCl full strength and a drip system for the strong peroxide, using agitation to constantly balance the peroxide in the solution.
> 
> And, small additions of strong H2O2 will jack up most dissolving reactions.



That's a very good point about adding more water than needed. More water is more to boil down and dispose of as well as having a slower reaction. Time and energy is money out of your pocket.


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## Lou (Nov 5, 2007)

Amen! Too much water can really be a pain. This stuff is available at all the pool supply houses I've tried (about 4 of them in my area) and it's pretty common stuff. It costs about $12-16 per gallon, depending on who's selling.


This is quite nice for taking care of large volumes, a Buchi rotary evaporator. It works by making a lot of surface area for the volatiles to evaporate (done by spinning the distilling flask in a hot water or hot oil bath). I started with 800mL of my Pd solution (about 101g pure metal dissolved there) and after 15 minutes of that, I was down to about 300mL of nitric-free syrup.


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## Noxx (Nov 5, 2007)

Nice appartus :lol: But seems to be costly lol


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## Lou (Nov 5, 2007)

About $5400 new, but they can be had for a tenth of that on ebay.

Same is true of that flask in the background, new probably around $7800, on ebay (if you see one) about $780.


Did I mention that I sell glassware?


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## Noxx (Nov 5, 2007)

No you did not :lol:


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## Anonymous (Nov 7, 2007)

Had a look on Sigma_Aldrich site, here's what I found:

vapor density 1 (vs air)
vapor pressure 23.3 mm Hg ( 30 °C)
assay 99.999% (metals basis)
contains stabilizer
concentration 30-32 wt. % in water, semiconductor grade
density 1.11 g/mL at 25 °C
3.7 L $180.00 Can

Dunno if this will help, or if its the right grade.Certainly cheaper than the reagent price.

Cheers.... Stu


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## Anonymous (Nov 25, 2007)

Hello to all your helpfull guys!

First to Lou : send me your pricelist!

Secondly to Steve: As I told in my mail to you, I was afraid of the fumes: I intended to use HNO3 + 3HCL and was scared of all the NOXX'es. 
You said that you use Acid Peroxide in recovering AU from CPU's. Not only AP ???
I found a patent my self: http://www.freepatentsonline.com/6649070.html

I intend to recover in small scale : 0.5 kilos of 286-386 Intel chrushed CPU's at a time. Could anyone give me the exact recipies of chemicals needed. 
I'll purchase your DVD tomorrow. Can I pay and downlod the complete DVD on my high-speed PC?
I'am surfing around on this forum : learning a lot, but confused somtimes too. Thank you from a ritired engeneer from Norway.


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## lazersteve (Nov 25, 2007)

Qio,

Welcome to the forum.

You should read the newbies guide to the forum for starters:


Guided Tour

Steve


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## Anonymous (Nov 25, 2007)

Thank You Steve.

I will use some hours to day on the guided trip.


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## skyline27 (Dec 8, 2007)

Will stronger acid peroxide be more likely to put gold into solution? (processing fingers)


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## lazersteve (Dec 8, 2007)

Yes. 

The stronger the peroxide the more likely the gold foils will be dissolved. 

If the peroxide is strong enough all the foils will be dissolved and mixed with the base metals. When the bulk of the base metals absorb into the solution they will most likely precipitate the dirty gold back out as a fine black/brown powder. It's similar to the balance in the other dissolving reactions where excessive oxidizer will keep the gold dissolved until the oxidizing chemicals are used up.

This dirty gold powder will still need to be redissolved to refine to 24kt. If you want to dissolve your gold foils using just HCl and strong H2O2 (hydrogen peroxide) that would be a slower, yet an acceptable alternative to HCl-Cl or AR.

Steve


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## Never_Evil (Dec 9, 2007)

Almost sounds like if you use the higher concentration Hydrogen peroxide, throw in a penny to be absorbed into the solution and push out the gold. 

For people that dont want to commit a crime and destroy a penny (pure copper ones are 1982 and earlier) toroids on computer mother boards can be used. Toroids are those round hoops with copper wrapped on the outside of them. Simply crush the ring(its brittle) and you can unfurl the copper wire and use that to precipitate out the gold with strong H2O2. You can also use this wire to cement out silver instead of copper pipe. More will be needed, but when its free from the computer versus buying it at a hardware store, the savings add up.


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## lazersteve (Dec 9, 2007)

Evil,

I would *not* recommend using copper to precipitate gold from any solution as the copper tends to contaminate the gold powder and you never get your gold pure. You would be defeating the purpose of refining if you use copper to precipitate gold. Plus the copper will also form other precipitates like copper (I) chloride when the solution becomes saturated with copper. This is the familiar of white powder you may have seen in the foils after using AP.

Copper wire is not a good choice for cementing silver due to the fact that it is thin and tends to break up into smaller pieces of copper which ultimately do not dissolve and end up mixed in with the silver powder. This is why a copper bus bar or some form of thick copper is specified in the cementing process.

When choosing a precipitant always look for one that is specific to the material you want to precipitate with little or no other side reactions.

Steve


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## Never_Evil (Dec 9, 2007)

Thank you for that valuable information. That will save me and others a lot of frustration.


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## skyline27 (Dec 9, 2007)

Has anyone used strong hydrogen peroxide and HCl with cpus or pins? It seems like this would be more user friendly than full blown AR, if it worked.


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## Anonymous (Dec 10, 2007)

Hello Skyline

I really hope that this works . I plan to refine a garage full of disks, boards and CPU's, and this peroxide-methode seems less dangerous...

To Steve : The DVD and Hokes book arrived safely Norway. I hope if I have some questions I can ask. Thank You.


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## lazersteve (Dec 10, 2007)

Qio,

I'm glad you got the book and DVD okay.

I can assure you that AP will work with CPUs and other gold plated electronic scrap. 

I will be happy to assist you anyway I can.

Steve


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## eagle2 (Dec 11, 2007)

Hi Qio: I would like to add a point, that once the AP process has loosened all the gold foils on your scrap, remove the barren scrap and cool down the solution and residues to near around 5-10 deg. C.

This will precipitate most of the gold held in solution, overnight. There may be so little left, its not worth working further. 

Al


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## EVO-AU (Sep 11, 2008)

Buzz: I was browsing the forum and came across your Chinese Yin/Yang symbol. Are you by any chance a practioner of the arts ? EVO-AU


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## Buzz (Sep 11, 2008)

Hi EVO,

Not really, it's the wife that studies all that stuff!

We have a very large piece of artwork in the house that looks almost identical to my avatar. 

The wife is the most methodical, balanced, chilled out girl i've ever met. I'm totally the opposite, which according her, is the reason we are still together after all this time! 

Dunno, maybe there's something in it if she can put up with me for 30 odd years! lol :lol: 

Regards
Buzz


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## DNIndustry (Nov 17, 2008)

I now where a rotatry evaporator is for $100.

And a UV mass spec for $300


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## lazersteve (Nov 17, 2008)

I'm interested in a complete rotovap.

Will you PM me the information?

Steve


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