Precipitate tin and copper selectively

[Martijn]

And those radiators look more stainless sheet metal than aluminum to me.

Also carefull with that cooling paste on the copper bottoms. Some of them can be toxic.

The weirdest materials are used in electronics, even more so in industrial stuff, just to make a device work better, and this makes scrapping risky. Know what you are doing and if it's worth your time, money and the risks involved.

If you get a really "good" deal, think twice and do some research before you're stuck with a polluting disaster only corrupt third world low wage/modern slavery countries would accept.

On the other hand, investigate how to recycle them and ask the government to subsidize you less polluting way, by not sending trash to the dark corners of the world. We need a new approach in so many ways imo.

 

[Yggdrasil]

I think the 35C per Kilogram is because of the heat transfer liquid that is in these heatsinks that make recovery and most important these days: environmentally friendly waste disposal more difficult than with solid aluminum and copper heatsinks.
Be very carefull and very responsible please!!

Applying melting heat to it may not be your best option.
first concern I would have is> what is in it exactly? Then make a plan about heating or smelting based on those material properties..

Another point; molten (base) metals are great solvents for precious metals and other base metals.
Solubility of copper in molten aluminum is about 5%, but lead and tin can absorb a lot more, so melting one metal and leaving the other intact can be a challenge. you could make an alloy that is harder to separate.

E.g.: when you melt lead with gold, the gold will go in solution at around 300C in stead of its melting temp of about 1000C !!

I'm not convinced there are anything inside most of these coolers.
I have snapped off a couple and there has been no liquid nor gas inside those.
I think they use tubes rather than solid Copper because there are less material and thus cheaper, but the Copper itself is what conducts the heat.

 

[mr.data]

I think the 35C per Kilogram is because of the heat transfer liquid that is in these heatsinks that make recovery and most important these days: environmentally friendly waste disposal more difficult than with solid aluminum and copper heatsinks.
Be very carefull and very responsible please!!

Applying melting heat to it may not be your best option.
first concern I would have is> what is in it exactly? Then make a plan about heating or smelting based on those material properties..

Another point; molten (base) metals are great solvents for precious metals and other base metals.
Solubility of copper in molten aluminum is about 5%, but lead and tin can absorb a lot more, so melting one metal and leaving the other intact can be a challenge. you could make an alloy that is harder to separate.

E.g.: when you melt lead with gold, the gold will go in solution at around 300C in stead of its melting temp of about 1000C !!

Yes the eutectic system you are referring to.

I want to have the, what I think is tin, melted or leached from the copper before melting the copper itself but I don't know if there are other metals in there as well. Maybe its alloyed to give other properties.
Do you know how I can determine which metals they exist of?

 

[Yggdrasil]

Yes the eutectic system you are referring to.

I want to have the, what I think is tin, melted or leached from the copper before melting the copper itself but I don't know if there are other metals in there as well. Maybe its alloyed to give other properties.
Do you know how I can determine which metals they exist of?

I am not sure it is Tin in the Solder for Copper Aluminum.
It is more likely to be a direct friction brazing.
I might be wrong though.

 

[anarxi]

There is a lot of CPU coolers here and my plan is to shred them, put them in a HCl solution and let it dissolve over time.
I will end up with a solution of tin, aluminium and copper if everything goes according plan.
Is there a method to precipitate the tin and copper out of the solution seperately?

option #2

you need to dissolve aluminum, tin and copper in an alkaline solution, and then reduce the tin by electrolysis.
copper will remain intact + there will be a lot of hydrogen...

 

[anarxi]

By the way, are you sure that this is aluminum?
maybe it's a ZAMAK alloy?

 

[mr.data]

option #2

you need to dissolve aluminum, tin and copper in an alkaline solution, and then reduce the tin by electrolysis.
copper will remain intact + there will be a lot of hydrogen...

I need to dissolve aluminium, tin and copper in alkaline solution but the copper stays in tact.
If I dissolve it, how does it stays in tact?

 

[Marcel]

I used to design those heatsinks in the late 1990s. There was a lot of silver involved as solder to connect copper and aluminum. Have you also checked for that?

 

[anachronism]

I used to design those heatsinks in the late 1990s. There was a lot of silver involved as solder to connect copper and aluminum. Have you also checked for that?

No Marcel I haven't = I will now ;-)

 

[Martijn]

I need to dissolve aluminium, tin and copper in alkaline solution but the copper stays in tact.
If I dissolve it, how does it stays in tact?

Kind of obvious looking at the whole context, but i guess he means put the combination of attached metals in a solution that will dissolve it all, except the copper.
If the solder with silver in stead of tin will dissolve in alkaline solution, not sure. you will have to research or test it.

 

[Martijn]

I'm not convinced there are anything inside most of these coolers.
I have snapped off a couple and there has been no liquid nor gas inside those.
I think they use tubes rather than solid Copper because there are less material and thus cheaper, but the Copper itself is what conducts the heat.

It seems you are correct here. It was my assumption that all tube-cooling devices use nasty refrigerants, it appears some are vacuum evacuated capillary tubes, and some have plain water. I'm not sure that goes for all types, but it's reassuring to know.

 

[offtrailhiker]

tin is usually 3 times more expensive than copper.
it makes sense to bother...

On paper that is true. Here in USA the market for scrap Sn is weak. It generally pays about half of scrap Cu.

 

[offtrailhiker]

Yes, these are the coolers.
The other image shows the tin that is on there.
There is excessive amounts of tin used thats why I think its feasable to recover that as well

In my market I'd look for an AL/Cu radiator price. Make sure no Fe is present. Have you actually sold scrap solder for more than Cu value? I leave solder on since I'll get #2 Cu price either way.

 

[Marcel]

It seems you are correct here. It was my assumption that all tube-cooling devices use nasty refrigerants, it appears some are vacuum evacuated capillary tubes, and some have plain water. I'm not sure that goes for all types, but it's reassuring to know.

I think you are talking about heat pipes. They use a phase-change (vaporizing a liquid to a gas) effect to transport the heat energy from one end of the tube to the other one. It is a very effective process. The liquid that is best suited for that is isopropanol/alcohol. One could use water but that is less effective.

 

[Yggdrasil]

I think you are talking about heta pipes. They use a phase-change (vaporizing a liquid to a gas) effect to transport the heat energy from one end of the tube to the other one. It is a very effective process. The liquid that is best suited for that is isopropanol/alcohol. One could use water but that is less effective.

I even think they are best for stationary use as they need a height difference to let the liquid feed back to the hot end?

 

[snoman701]

On paper that is true. Here in USA the market for scrap Sn is weak. It generally pays about half of scrap Cu.

Very weak. Until you have thousands of pounds, and even then, it's not great. The tin price advertised is that for pure tin.

Now, there are some small quantity avenues to sell high tin alloys, but they are still difficult to find, and not scaleable.

 

[mr.data]

I used to design those heatsinks in the late 1990s. There was a lot of silver involved as solder to connect copper and aluminum. Have you also checked for that?

Not yet but I surely will figure out what's used in these. Do you know why they used silver for the tin alloy'?

 

[mr.data]

It seems you are correct here. It was my assumption that all tube-cooling devices use nasty refrigerants, it appears some are vacuum evacuated capillary tubes, and some have plain water. I'm not sure that goes for all types, but it's reassuring to know.

They are hollow most of the time when they have a distance to the fan. When they are closely attached to the fan they are often solid. I think that the distance would allow the heat to escape with less copper in terms of weight.

 

[mr.data]

In my market I'd look for an AL/Cu radiator price. Make sure no Fe is present. Have you actually sold scrap solder for more than Cu value? I leave solder on since I'll get #2 Cu price either way.

No I did not sell it before but I buy it on a regular basis and it's pretty expensive. I figured if I can get it out fairly easy, why not...

 

[Marcel]

Not yet but I surely will figure out what's used in these. Do you know why they used silver for the tin alloy'?

It is used to increase the heat transfer between two mechanically seperated layers, f.e between copper and aluminum. Often (always if done right) also the solder that attaches the heatpipe (copper pipe) to another component. The amount is rather small but the silver content should be very high.