Need your support (again) regarding cementing stockpot on copper.

[Proffshuggarn]

I'm probably stupid, or this about cementing out leftover acid mixture on copper is so much easier, that it becomes difficult. I have a tendency to overanalyze and I think the situation is like that now. I would be grateful for your views on this new situation. This is one (of many) piece of copper that has been in my stockpot with air pump for about 2 days. I scrubbed off the outermost green/white cement that was stuck very hard. I felt satisfied and collected a few grams of the green/white cement in a test tube, added about 5ml of hydrochloric acid... and just about EVERYTHING dissolved instantly. I thought that now I'm going to drop everything regarding this, because I'm obviously mentally retarded.. When I walked in, my wife called out to me: "-Dennis, come and see if you see what I see". She showed me the round piece of copper that I "almost cleaned". I've resigned myself to the fact that I almost threw away what at least seems to be what I'm looking for. I haven't been able to test with Stannous's test, because what at least looks like cemented gold is firmly attached and I'm afraid it's far too much copper in correlation to the potential gold alloyed? How would you have done in this case?
Apologies for the imperfect sharpness of the pictures.
/Dennis

I know it’s a small amount potentially value that seems cemented, but many of those should in time be something

 

[Yggdrasil]

I'm probably stupid, or this about cementing out leftover acid mixture on copper is so much easier, that it becomes difficult. I have a tendency to overanalyze and I think the situation is like that now. I would be grateful for your views on this new situation. This is one (of many) piece of copper that has been in my stockpot with air pump for about 2 days. I scrubbed off the outermost green/white cement that was stuck very hard. I felt satisfied and collected a few grams of the green/white cement in a test tube, added about 5ml of hydrochloric acid... and just about EVERYTHING dissolved instantly. I thought that now I'm going to drop everything regarding this, because I'm obviously mentally retarded.. When I walked in, my wife called out to me: "-Dennis, come and see if you see what I see". She showed me the round piece of copper that I "almost cleaned". I've resigned myself to the fact that I almost threw away what at least seems to be what I'm looking for. I haven't been able to test with Stannous's test, because what at least looks like cemented gold is firmly attached and I'm afraid it's far too much copper in correlation to the potential gold alloyed? How would you have done in this case?
Apologies for the imperfect sharpness of the pictures.
/Dennis
View attachment 57262View attachment 57263View attachment 57264View attachment 57265
I know it’s a small amount potentially value that seems cemented, but many of those should in time be something

Any values will be as dark mud.
Have these been lying around for a while in air?
I have never seen green copper coming out of a stock pot
What is sticking to the surface of these "ingots" seem to be various iterations of Copper Chlorides and/or other Copper Salts.
What pH was the solution?

 

[Proffshuggarn]

Have these been lying around for a while in air?

Yes Sir, about 2-3 days. And they have turned more green during those days.
They was more like white colored when I picked them up. The cemented green/white cracked up in flakes when I bended on the more flat copper plates also lying in there. And the gold-like “crystals” is under that cement.

What pH was the solution?

pH was 2-2,5 when I picked them up. From start 48h earlier pH was 1.

I’m going to siphon off that tub today, though I stopped the “bubbler” yesterday.
Maybe there’s some black on the bottom then.
/Dennis

 

[Yggdrasil]

Yes Sir, about 2-3 days. And they have turned more green during those days.
They was more like white colored when I picked them up. The cemented green/white cracked up in flakes when I bended on the more flat copper plates also lying in there. And the gold-like “crystals” is under that cement.

pH was 2-2,5 when I picked them up. From start 48h earlier pH was 1.

I’m going to siphon off that tub today, though I stopped the “bubbler” yesterday.
Maybe there’s some black on the bottom then.
/Dennis

A day or so should be sufficient when you have a bubbler.

 

[Proffshuggarn]

A day or so should be sufficient when you have a bubbler.

-Thank you Yggdrasil

 

[Alondro]

I have seen copper become encrusted with white salts in waste that had a large amount of other base metals aside from copper dissolved in it. They are likely complexes of multivalent metal cations, there's also tin oxychloride which can form in certain circumstances.

 

[dannlee]

I had blue-green out the wazzoo when a plated brass jewelry chain got included on my first scrap run - I finally recovered 3.5g Au from 11g batch, dry roasted everything and then excesses of HCl and water washes finally cleared it -

 

[orvi]

I have seen copper become encrusted with white salts in waste that had a large amount of other base metals aside from copper dissolved in it. They are likely complexes of multivalent metal cations, there's also tin oxychloride which can form in certain circumstances.

White stuff associated with copper is most of the times cuprous chloride. If we talk about regular waste from pins and stuff. During cementation on copper, acidity drops to practically zero free acid (does not mean pH is high, only that free HCl isn´t very much present; aquated complexes of base metals are acidic on their own), and this is a problem, as many times lots of junk precipitates out of the solution. Colour of the solution is good lead. Darker colour in Cu2+/Cu+ solutions means more Cu(+).

That is why I prefer quick cementation on copper when solution is still hot. It does not take days if you have good setup. Many times with some stirring it is done in matter of hours, if we are talking about concentrations of PGMs not higher than few g/L.

 

[Proffshuggarn]

That is why I prefer quick cementation on copper when solution is still hot. It does not take days if you have good setup.

Thanks Orvi. It seems like my bubbler is very effective then, it’s circulating/stirring the liquids in the whole tub very good. I did only check the pH and secured the double air hoses on the bottom of the tub, then I thought I’ll go back there in about 2-3 days and have a look if something has happened. Next batch I will stand ready beside the tub to instantly pull up the copper like a pike when I’m fishing.
This evening did I spent in the “lab” filtering the massive amount of white tin/copper jelly that actually did keep some hidden gold from the pins and connectors that someone () put in there. And obviously with a lot of solder on as well... Then I think I’ve learned something today again.
Thanks
/Dennis