Acid Peroxide Process Information Thread Q & A's

[Geo]

Dirt and dust poses no problems but oil does. If the fingers are oily, wash in some warm water with dish soap. Rinse well before putting them in AP.

 

[scranney]

That was quite funny.
Thanks.

Do you think that putting activated charcol in the scrubber is fine for the ap solution and the hci and bleach?

 

[jason_recliner]

If the fingers are oily, wash in some warm water with dish soap. Rinse well before putting them in AP.

Or just wear gloves. :lol:

Edit: Ug, joke already been made. :|

 

[Geo]

Ahhh. I get it. :lol: Walked into that one backwards.

 

[solar_plasma]

Ok, I am not an expert in scrubber systems, but since no one else answers:

HCl vapors and clorine gas.

Activated carbon alone will hold them more or less for a comparably short time, but you don't know, when the filter has its break through.

Both would react with lyes, which can be monitored by pH. But chlorine will form hypochlorite, which again will release chlorine, if the solution ever would get acidified. Just something to have in mind.

On the other side, chlorine can be used to oxidize iron II chloride to iron III chloride, which again is nice for dissolving basemetals. I don't know, if this is practical. But this is, what I would use chlorine for, if I had a lot of it dailly.

There has been written a lot about scubbers, I am sure, if you search deep enough, you will find more and better information.

 

[Geo]

If you plan on using nitrates of any kind, you should rethink charcoal. Those are two of the major ingredients for gunpowder.

 

[solar_plasma]

And activated carbon is useless for scrubbing NOx.

 

[solar_plasma]

For me it is most practical to catch gasses in a closed system in the next vessel with a matching reagent before letting them pass through the fume hood.

Another important point is, you should always use small increments of hypochlorite at a time when dissolving gold, added with a pipette at the bottom of the solution, so if you do it right, there won't be much chlorine left over, that can escape.

 

[scranney]

Thanks for all the help

 

[Bretl]

Hello my name is Bret I don't know if this is the correct place to put this and it may be posted already as I am new to the forum and would like to make sure that people do not use acetone(ketones) to strip the grease off scrap parts when using acid and peroxide it can create a very explosive compound that is heat and shock sensitive thanks and I hope this helps someone

 

[saadat68]

Hi
Some people here, said tin go to AP solution in form of stannous chloride and some people said tin oxidize in AP solution and produce tin oxide. Maybe both?!

1- Which is correct? ( I think tin oxide is correct because when we produce stannous testing solution, we must keep it out from air )
2- If tin in AP produces tin oxide, is it SnO or SnO2?

Thanks

 

[butcher]

Tin with HCl
Sn + 2HCl --> SnCl2 + H2
stannous chloride and hydrogen gas

But we are not discussing dissolving tin in HCl, But the oxidation of tin in a copper II chloride solution.

Sn + CuCl2 = Cu + SnCl2

The tin dissolves as stannous chloride while it reduces the copper ions to metal.

The tin salt can reduce many metals (including your gold as colloidal gold).
2AuCl3 + 3SnCl2 -->3SnCl4 + Au (colloidal)

Now from here, we can get into many different reactions depending on conditions...

SnCl2 + CuCl2 --> SnCl4 + CuCl
SnCl2 + 2CuCl -->SnCl4 + 2Cu
SnCl2 + 2FeCl3 -->SnCl4 + 2FeCl2
SnCl2 + H2O --> Sn(OHCl) + HCl
6SnCl2 + O2 + 2H2O --> 2SnCl4 + 4Sn(OH)Cl

well, we could keep going as we get many reactions so many of which become several become very complicated, and all conditions of solution really dictates the different reactions.

Tins chemistry is complex enough in pure solutions or reactions, but more complicated as the solution also becomes a more complex ionic soup of metals and acid, and the conditions (external and internal) of the soup itself change in its chemistry and conditions also dictate the oxidation state of the tin ions...

 

[bengie84]

Morning guys and girls

So this morning gone to do some filtering opened up my 3gal bucket to find a good layer for of oxidised copper on to floating green in my AP which until now I been using for around 4 months
So my question is has anyone else ever had this and how do I proceed to either clean the solution without fouling it to be able to reuse it or is it time to treat and dispose of it
Cheers ben

 

[kernels]

Adding some fresh HCl should clear it up, try it on a small sample first to confirm.

 

[torch01]

Steve thanks for the wonderful tutorial. You write that AP can be used indefinitely if carefully used. I come across scrap that is suitable for AP occasionally. Can I just process material in the AP as I receive it but leave the gold in there until I have an amount that I want to take to the filtering stage? And also can I leave the gold in there even during the copper removal from the AP stage? Thanks, Wayne.

 

[g_axelsson]

Steve thanks for the wonderful tutorial. You write that AP can be used indefinitely if carefully used. I come across scrap that is suitable for AP occasionally. Can I just process material in the AP as I receive it but leave the gold in there until I have an amount that I want to take to the filtering stage? And also can I leave the gold in there even during the copper removal from the AP stage? Thanks, Wayne.

Yes.. and don't know.

I run copper chloride that way. Add fingers when I get them, remove any that is cleaned and the foils accumulate at the bottom.

Indefinitely is a point of view. You need to add fresh acid sometimes and sometimes water. The volume will grow over time to hold all dissolved copper. Eventually you will reach a point when you have to pour off some of it. Take that overflow and process for copper and waste, that will leave the main leach working as long as you like.

I don't know what you mean with "copper removal from the AP stage", for me I recover the copper when I process the waste, not a minute before that.

When you are ready to process the gold foils, pour off the majority of the copper chloride and store it properly until next time you want to use it. Then process any gold left in the bottom of the beaker.

Göran

 

[torch01]

Thank you Goran. That helps a lot.

 

[bengie84]

Hey guys so for past few months had no issues with my Ap now all of a sudden it’s started foaming quite bad trapping gold foils in it and sticking them everywhere is there anyway to prevent the foaming or is that it the solution
Thanks again guys

 

[lazersteve]

Sounds like you may have added a different type of muriatic acid, possibly the fume safe variety.

Another possibility is that one of your types scrap you process introduced another chemical in the mix which caused the foaming.

Foaming to me also sounds like addition of excess iron to the AP solution, especially if it is rust colored foam.

In the above cases you may be able to save the batch of AP by filtering out the foam along with removing any solid pieces of iron that may be in there. Once you have eliminated the source of the foaming reaction, freshen up the AP with a good dose of fresh muriatic acid followed by the water test (white cloud indicates copper saturation). If you see the whitish gray particles when water is added, them add more O2 via bubbler or peroxide to bring the AP back to a transparent green color as opposed to dark black/brown.

Steve

 

[bengie84]

Thanks steve
All scrap is the same I have not purposely added any iron and was carful when checking what went in the liquid is still green but very dark and the foam is also green to white as for the acid it all came from one 5lt (uk gallon) bottle but I will try and skim off the foam and filter see if that helps at all