Non-Chinese PCBs

[Lou]

One thing we often recommend for people looking to upgrade the Cu content in their bars for electrolytic parting is to use reverse cementation (copper sulfate). This removes the iron, aluminum and zinc. Alternatively, one can blow air through the melt but that's a slaggy process.

Most of the tin can be fluxed out with the appropriate basic flux (tin is quite a bit more reactive with alkali fluxes than copper, and gold/silver completely untouched when copper is in such excess).

Not a big fan of borax on melts like this. Borax (and silica) are good for iron removal, but the flux is a very viscous glass than leads to entrainment of PMs.

 

[ericrm]

i was wondering what happened with your assay? you did try to melt a lot of different boards on different tread but suddently you stopped posting? i would bet that everybody is impatient to see your result

 

[kjavanb123]

Ericm,

The alloys are sent to the lab called them this morning and they said will be ready by Saturday next week which I shall post in approprate posts.

Thanks
Kevin

 

[kjavanb123]

One thing we often recommend for people looking to upgrade the Cu content in their bars for electrolytic parting is to use reverse cementation (copper sulfate). This removes the iron, aluminum and zinc. Alternatively, one can blow air through the melt but that's a slaggy process.

Most of the tin can be fluxed out with the appropriate basic flux (tin is quite a bit more reactive with alkali fluxes than copper, and gold/silver completely untouched when copper is in such excess).

Not a big fan of borax on melts like this. Borax (and silica) are good for iron removal, but the flux is a very viscous glass than leads to entrainment of PMs.

Lou,

Please kindly advise for reverse cementation the refiner bar would be at cathode and a pure sheet of copper would be anode with electrolyt consists of copper sulfate.

Thanks
Kevin

 

[ericrm]

kjavanb123, it is cementation, it is common knowledge if you read the forum, what hapen if you cement copper salt with iron??? copper become metalic and the metallic iron replace copper as a salt... plz advise please do some work from your side...

 

[niteliteone]

Generally I am able to understand what is written here on the forum, But these 2 posts don't sound like they are talking about the same thing here.
Can someone explain further if and how these are the same or different statements :?:

Lou wrote:
One thing we often recommend for people looking to upgrade the Cu content in their bars for electrolytic parting is to use reverse cementation (copper sulfate). This removes the iron, aluminum and zinc. Alternatively, one can blow air through the melt but that's a slaggy process.

kjavanb123, it is cementation, it is common knowledge if you read the forum, what hapen if you cement copper salt with iron??? copper become metalic and the metallic iron replace copper as a salt... plz advise please do some work from your side...

 

[butcher]

I have to admit sometimes I also have a hard time understanding some comments, and I am really not sure about this one either.

 

[ericrm]

sorry if i was hard to understand, and maybe lou is talking about something else ... if that is the case well lou will probably explain it ... but for what i understand when you have a mix of different metal containing pm ,and you wish to add copper and reduce the amount of the other base metal ,you could be using an acid solution containing a copper salt. the reaction will be the cementation of the copper over the undesired other base metal... so rather than cementing the value out you cement the base metal out (in this case copper)

 

[niteliteone]

Ericm,
How would you "cement" copper out of a solution containing PM's without cementing the PM's along with the copper :?:
I don't remember reading how to do that.

 

[g_axelsson]

It's cementing copper onto scrap pcb:s -> iron, zinc, tin, lead and aluminum goes into solution while copper is cemented. Then when you melt the board you get a copper bar with higher amount of copper than you would ordinary get.

Both Lou and ericrm is talking about the same thing.

Göran

 

[butcher]

Göran,
Thanks I guess I missed the main part of the discussion, the circuit boards, that clears up my confusion.
lead would form insoluble sulfate.

 

[g_axelsson]

Thanks, I had forgotten about lead sulphate being insoluble. I just started to go through some of the major metals you will find on a circuit board and in the end made a fool out of myself. 8)
Lead will cement the copper, turn into insoluble lead sulphate. But I wonder if not lead sulphate will turn into lead oxide, litharge, when melting the metals together so it mostly doesn't end up in the final metal bar.

Another twist on this method could be to use copper chloride from the AP process. That is exactly what I use to take the pins off P4 and other modern fiber CPU:s where the pins are soldered onto the surface. In just 10-20 minutes you can scrape off the pins. The tin dissolves and the pins are now covered in a crust of copper.
It is a good way to finish off old contaminated copper chloride solution before treating the waste.

Göran

 

[butcher]

Göran,
When posting sometimes we do not always think every thought through, (we all make mistakes, if we didn't, we wouldn't be doing anything), I know you knew lead sulfate is insoluble and you were just not thinking about it at the time you posted, I didn't think much about it, but thought I would mention it for those who did not know.

The copper chloride solution would work, it would also make an insoluble white powder of lead chloride, but the lead chloride powder can be dissolved in hot water, where lead sulfate cannot.

 

[g_axelsson]

We all write for our audience. 8)

Göran

 

[niteliteone]

Thanks for the explanation Göran and Butcher.
Now I can honestly say I learned something today. (I hope)
I would assume this is to be done before the PCB's are incinerated as per this thread, as it would help lower base metal content of the PCB's "and" increase overall copper content of the metals after the incineration.

 

[Platdigger]

Some how I don't think this is what Lou was talking about.
He said to upgrade the "bars". In other words, bars that are all ready poured.
At least this is how I read it.

 

[freechemist]

Apparently there seems to be quite a bit of confusion about this thread.

November 7th, 2013, Lou suggested:

One thing we often recommend for people looking to upgrade the Cu content in their bars for electrolytic parting is to use reverse cementation (copper sulfate). This removes the iron, aluminum and zinc. Alternatively, one can blow air through the melt but that's a slaggy process.

December 2nd, 2013, niteliteone wrote:

Ericm,
How would you "cement" copper out of a solution containing PM's without cementing the PM's along with the copper? I don't remember reading how to do that.

December 2nd, 2013, g_axelsson wrote:

It's cementing copper onto scrap pcb:s -> iron, zinc, tin, lead and aluminum goes into solution while copper is cemented. Then when you melt the board you get a copper bar with higher amount of copper than you would ordinary get.

Both Lou and ericrm is talking about the same thing.

and further on:

Thanks, I had forgotten about lead sulphate being insoluble. I just started to go through some of the major metals you will find on a circuit board and in the end made a fool out of myself.
Lead will cement the copper, turn into insoluble lead sulphate. But I wonder if not lead sulphate will turn into lead oxide, litharge, when melting the metals together so it mostly doesn't end up in the final metal bar.

December 3rd,2013, Platdigger wrote:

Some how I don't think this is what Lou was talking about. He said to upgrade the "bars". In other words, bars that are all ready poured.
At least this is how I read it.

As far as I am able to judge it, Lou meant, to add copper sulfate to the melt, thus "upgrading" it with metallic copper, and removing other, unwanted base-metals out of the metal-phase, these being oxidized and so transferred as cations (e.g. Fe³⁺) into the flux-phase, whereas metallic copper (from added copper salts/oxides) enters the metallic phase. Such a procedure would replace the slaggy process of blowing air through the melt.
Where I worked, it was a quite general procedure in similar smelting processes, to add copper oxide(s) to the melt, using either copper-(I)-oxide or copper-(II)-oxide.
A "cementation-reaction" must not necessarily occur in an aqueous solution, if it is also understood quite generally as a redox-reaction involving a more precious metal (e.g. copper, as copper oxide) dissolved in the flux-phase and a less precious metal from the metallic phase (e.g. iron, tin, zinc).

 

[ericrm]

Apparently there seems to be quite a bit of confusion about this thread.

November 7th, 2013, Lou suggested:

One thing we often recommend for people looking to upgrade the Cu content in their bars for electrolytic parting is to use reverse cementation (copper sulfate). This removes the iron, aluminum and zinc. Alternatively, one can blow air through the melt but that's a slaggy process.

December 2nd, 2013, niteliteone wrote:

Ericm,
How would you "cement" copper out of a solution containing PM's without cementing the PM's along with the copper? I don't remember reading how to do that.

December 2nd, 2013, g_axelsson wrote:

It's cementing copper onto scrap pcb:s -> iron, zinc, tin, lead and aluminum goes into solution while copper is cemented. Then when you melt the board you get a copper bar with higher amount of copper than you would ordinary get.

Both Lou and ericrm is talking about the same thing.

and further on:

Thanks, I had forgotten about lead sulphate being insoluble. I just started to go through some of the major metals you will find on a circuit board and in the end made a fool out of myself.
Lead will cement the copper, turn into insoluble lead sulphate. But I wonder if not lead sulphate will turn into lead oxide, litharge, when melting the metals together so it mostly doesn't end up in the final metal bar.

December 3rd,2013, Platdigger wrote:

Some how I don't think this is what Lou was talking about. He said to upgrade the "bars". In other words, bars that are all ready poured.
At least this is how I read it.

As far as I am able to judge it, Lou meant, to add copper sulfate to the melt, thus "upgrading" it with metallic copper, and removing other, unwanted base-metals out of the metal-phase, these being oxidized and so transferred as cations (e.g. Fe³⁺) into the flux-phase, whereas metallic copper (from added copper salts/oxides) enters the metallic phase. Such a procedure would replace the slaggy process of blowing air through the melt.
Where I worked, it was a quite general procedure in similar smelting processes, to add copper oxide(s) to the melt, using either copper-(I)-oxide or copper-(II)-oxide.
A "cementation-reaction" must not necessarily occur in an aqueous solution, if it is also understood quite generally as a redox-reaction involving a more precious metal (e.g. copper, as copper oxide) dissolved in the flux-phase and a less precious metal from the metallic phase (e.g. iron, tin, zinc).

plz tell more ,i didnt knew that, how does the copper sulfate react? does the iron become a sulfate in the slag or does the "sulfur making the sulfate part" become something else?

 

[Smack]

Lou was talking about working with ground up electronic material, prior to melting and the copper cell not with chemicals.






For accuracy

 

[niteliteone]

Lou was talking about working with the melt not with chemicals.

Now it makes since

Freechemist
Thanks for clearing up the confusion.
I was doing all right until the mention of ""reverse cementation"" being a chemical enhancement of the copper before melting, which started my questions.

Thanks guys