Filtered material from green fiber CPUs with AP

[Mcnew32(Ag)]

Hello, I recently dropped pins from about 5 lbs of green fiber CPUs without the heat sinks using old AP solution with a aquarium bubbler. It took about 48 hours to completely drop off all pins and monolithic capacitors. After I filtered off the liquid through coffee filters, I was left with three filters full of black brown sludge with some gold foils mixed in them. A majority of the pins remained in the bottom of the bucket some fully gold plated pins but most are copper colored or black colored pins. My question is what is the best way to process the black sludge filters and reclaim the gold trapped inside? Also would heating the remaining pins in HCL be the best way to deal with the remaining pins?
I have since thrown the remaining pins back into AP along with some other various played pins from circuit boards just to begin the treatment process.

 

[Barren Realms 007]

If that middle picture is supposed to be your AP bucket after the CPU's dropped their pins then I would suggest you put your pins in new HCL because the HCL in the bucket looks used up or full of tin.

If you are able to separate your pins from the capacitors run do that and then put the pins in your fresh HCL.

I would put the filters and their contents in a separate container with fresh HCL and on heat probably about 2-3L.

 

[Mcnew32(Ag)]

Ok, thank you for your reply. That's what I was thinking about doing. I added about 250ml of fresh HCL to the AP solution. So when I get some time I'll heat the remaining pins in HCL and separate the capacitors. Just figured I'd throw the remaining pins in the AP because it's gunna be a couple days before I can get to the pins.

 

[Pantherlikher]

I think I see that you have full memory sticks in the 2nd picture.
Does this mean you are putting everything right into AP?

Instead of the mess with gold flakes like you now have; I put it in HCL overnight and heat before removing, rinsing, and separating.
This removes solder and anything else that will dissolve.

The whole object is to remove all base metals. What you did and the way I describe will use the same amount of acids but you still have all base metals and flakes in the same mix. HCL and then separation and into AP will remove base metals and keep your mess out from the flakes you're trying to get.

The first batch of memory sticks I did as a learning experience, I soaked in only HCL which unsoldered everything allowing easy separation.

Now you AP(ed) everything and still have all metals in the mix to get rid of. Makes it tougher to filter as well.

B.S.

 

[Mcnew32(Ag)]

Yes like I said it's going to be a couple days before I get to the pins so I figured just throw them
In AP and let the remaining acid eat away at the dissolvable metals before I can deal with the pins properly. The ram I threw in is just a few to see how long it takes the AP to clear the boards. Just a test run if you will. The solution is already loaded with tin and iron. Figure once I'm done dissolving what I can with this AP I'll filter all solids and pack it with stainless to drop out any copper or silver.

 

[Grelko]

Figure once I'm done dissolving what I can with this AP I'll filter all solids and pack it with stainless to drop out any copper or silver.

If you don't mind, I'm going to quote what Geo said in one of my posts about my AP and stainless.

Stainless steel is a poor choice for cementing copper. Use just plain steel. Stainless will be slow to react and is more expensive than scrap steel.

(I forgot to tell him that I collect scrap and get stainless for free)

Edit - Your bucket definately looks like it's full of tin. Mine had that same cloudy grey color a while back while processing pins

 

[Mcnew32(Ag)]

Ok I figured it would get saturated with tin more than copper. I collect a lot of scrap metal as well so stainless isn't a big deal. I didn't know it reacted slower than iron so that is definitely a factor. This weekend I will process the remaining pins and post pictures. Like I said just wanted to use up what was left of the acid solution before I set it aside for base metal reclamation.

 

[Grelko]

If you're interested, this post is my attempt at using AP to dissolve 3.5 pounds of mixed pins "plus other things". There's alot of good information there because I kept having problems. So far it's up to 104 posts and there will be more seeing that I'm not quite finished with them yet.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=22285

 

[Mcnew32(Ag)]

Ok I'll take a look thank you.

 

[Anonymous]

I agree with both Panther and Barren.

Put your product into some dilute clean HCl for long enough to remove things such as solder before moving on to recovery (by whatever method you choose to use.) I also get rid of any steel wires that are still attached at this point as well once the HCl has done its work.

This way you'll end up with less gunk and things like Tin going into your further procedures. It makes life a "shedload" simpler.

Jon

 

[g_axelsson]

I agree with the above members. I just did 2 kilos of ram to test chemical depopulation of boards. It worked like a charm. Just pure HCl at first to remove the tin that holds the components, then the copper chloride process to get the gold from the boards.

The sludge left behind when dissolving the tin contains some gold too, so I saved it but it was less than a ml from half a liter of acid. Not the amount of sludge that you managed to produce.

Did you use peroxide? Your copper chloride (aka AP) leach is very weak in color. I suspect that you did and that the peroxide oxidized the stannous chloride into metastannic acid.

Göran

 

[Mcnew32(Ag)]

I did use peroxcide at first. But slowly stopped using it and just kept the bubbler going. I noticed that as soon as I added the ram sticks the gold plating turned copper color almost instantly.

 

[Geo]

I did use peroxcide at first. But slowly stopped using it and just kept the bubbler going. I noticed that as soon as I added the ram sticks the gold plating turned copper color almost instantly.

That is very common. The gold should be safe under the discoloration.

 

[Pantherlikher]

I did use peroxcide at first. But slowly stopped using it and just kept the bubbler going. I noticed that as soon as I added the ram sticks the gold plating turned copper color almost instantly.

That is very common. The gold should be safe under the discoloration.

1 major loss problem I see here. HCL + Peroxide dissolves tin. HCL + Peroxide dissolves gold = tin tying up gold to make very difficult to get gold. How do you test for gold in solution?

Most important reason to get rid of as much base metal as you can before any chance of gold dissolving.

The AP process begins with HCL and only a small amount, teaspoon or so, of Peroxide. Once copper begins dissolving, you add air off it goes.

Remove all solids Now... Treat solution as waste. Next, go back and read removing solder and why. Then move on to learning the AP process for gold "collection".

B.S.
...Do what is proven to work and not just get close enough thinking it is good enough...

 

[Mcnew32(Ag)]

Ok, I'll be working on this today. Heating HCL to dissolve remaining pins and filter off foils. Any advice for processing the contaminated filters?

 

[MarcoP]

Give butcher a read too http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=22875&p=240073#p240073

Marco