Question about RAM depopulation with HCL

[Bluebloomer]

Hi all !

I've got 13 lb of misc PC RAM sticks. Been busy for a while to depopulate them; first with a chisel to remove the MMLC, and then remove the chips.
But as 13 lb is a heck of a lot ram sticks, I was hoping and wondering if it has been done before to remove the MMLC and the chips with hot hcl, and if it's any good or not..

I have been scrapping for the last 5-6 months, breaking each component down to collect what I need but hundreds of these ram sticks are a pain to do at a rate of like 15-20 pcs per hour..

So the idea was to use AP from a previous batch, and bring it to a simmer and wait till it all falls off. Then with a pair of tweezers take the chips out, and collect the MMLC by dropping it in a filter.
I do not realy want to boil it, just make the HCL hot enough to eat the legs of the chips.

Does this give issues with the MMLC to process them later for the Pd / Pt ? Can I just rinse the MMLC and process later, or do I have to process them right away as they are taken out of hot HCL ?
I know monolithics have to be boiled in clean HCL to start the recovery process, but I was hoping that AP would leave them intact so I can recover the pt/pd later.

Any experience or idea's on that ?

 

[Barren Realms 007]

I use used AP or old AR solution that the copper has been dropped out of. I put the RAM in a plastic bucket and fill to just above the RAM. Put he container on heat (160F-190F) and let it set for about 12-18 hours and then remove the chips. You can take a screen and separate the chip's from the MLCC's once they are off of the RAM sticks.

 

[MarcoP]

I use used AP or old AR solution that the copper has been dropped out of. I put the RAM in a plastic bucket and fill to just above the RAM. Put he container on heat (160F-190F) and let it set for about 12-18 hours and then remove the chips. You can take a screen and separate the chip's from the MLCC's once they are off of the RAM sticks.

That's interesting.

I suppose you used scrap iron to drop copper and now the solution would be full of iron. How would that work when the solution is full of iron which is higher then tin and lead in the reactivity series?

Just out of curiosity, recycling waste solution would be a great thing to learn.

Thank you.

Edit: cleaner

 

[necromancer]

here you go Marco

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=53&t=611

 

[Barren Realms 007]

I use used AP or old AR solution that the copper has been dropped out of. I put the RAM in a plastic bucket and fill to just above the RAM. Put he container on heat (160F-190F) and let it set for about 12-18 hours and then remove the chips. You can take a screen and separate the chip's from the MLCC's once they are off of the RAM sticks.

That's interesting.

I suppose you used scrap iron to drop copper and now the solution would be full of iron. How would that work when the solution is full of iron which is higher then tin and lead in the reactivity series?

Just out of curiosity, recycling waste solution would be a great thing to learn.

Thank you.

Edit: cleaner

Yes I use scrap iron to drop the copper that is in my solution's

There is generally a touch of copper left in my solution when I do this procedure.

There is enough free HCL in the solution that it works without any problem for me.

The solution is around 5% HCL because of the addition of water when the PM's were dropped from it's original use.

Don't get me wrong though that dosen't mean it will work for everyone that tries it.

 

[necromancer]

this is a better post http://goldrefiningforum.com/phpBB3/viewtopic.php?f=47&t=1300&p=40800&hilit=waste+for+the+small+refiner#p40800

 

[MarcoP]

Barren, thank you. I just had a couple of ideas to try to reuse acid before waste disposal.

Necromancer, few months ago I did printed out that post and read it over and over with additional readings outside the forum. I think I well learned that part of the job and that's where I learned to use calcium hydroxide instead of lye. Cheap and easier to filtrate. Thank you very much.

To answer the original OP's question. I did try, in small samples, to depopulate ram sticks and hard drive boards following many methods.

Warm HCl or HCl with a touch of used AP. In both cases there is was a lot of sludge in the bottom of the container. Most of it was ceramic coming from MLCCs, silver chloride, dirt and others. Moreover broken condenser means that some of the silver and of the palladium will be found in the sludge.
MLCC and resistors where in bad conditions, chips had to be very well rinsed otherwise after a day or so the remaining acid would keep oxidizing the legs releasing bad odors and making the look really bad. Additionally I've had to spend more time and acid to process the sludge, did it ones and won't do that again unless required.

[stt]Mechanical[/stt] Manual removal. Too much work and time for me.

Sand bath. In a couple of hours I was able to clean them all. I've used a sieve to separate ICs from MLCCs in few minutes.

Most experienced users would give you better advices but till now I'll keep using a sand bath even if that means wearing a respirator for the entire process. The outcome is a clean material where most of the dirt would be already removed by the sand and the heat.
I would reuse old acids to process the legs after the chips are incinerated, pulverized and separated from the rest of the material.
MLCC will be clean and easier to process with AP or your preferred method.

Hope it helps.

 

[Bluebloomer]

Thank you all for the given advice !

With an average weight of 25-35 grams per RAM stick it means I have to manually handle around 220 sticks, close to 1500 pieces of chips.
I also have around 160 motherboards to deal with and 400 PCI/ISA cards, so I don't mind too much to sacrifice some metals .
Already pulled a good 300 grams of MMLC and resistors from boards and cpu's so far, so if I loose some values from the ram sticks with the HCL method it's a small price to pay.

I can imagine that the solution will be saturated with nickel, copper, tin, some gold foils, and other metals but how would silver come into the solution and in what form ?

Perhaps a bucket with holes inside a bucket might separate the chips from the acid ..

@Barren: How do you heat the solution in a plastic bucket ? Nice to read that I didn't have a crazy idea this time, because I was afraid this idea might be considered lazy..

Why take the copper out of the CuCl2 and replace it with iron ? Will it make the HCL free of other metals so it can attack the legs of the chips better ?

@MarcoP: My experience so far tells me that recycling waste material is harder than a normal recovery but oh so necessary as I messed up some recovery processes so far..

I want to use a sand bath in spring to depopulate the motherboards, but since I have a few gallons of used acids I wanted to put it to use and not just use it to treat waste.
Good idea to treat the legs of chips with acid so the incineration will be easier, I'll remember that!
So you are saying that with the acid method you wind up with a solution with traces of PD/PT/AG/AU in solution? I thinks it's a small price to pay as you can save hours, days or perhaps even weeks of scrapping ram sticks by hand, but you would have to know how to treat the solids/acid after.

I want to try 1 batch with ram sticks I already cut in half after removing the gold fingers. Will the presence of HNO be a big problem? I'm fairly sure it's just AP but I also have HCL with Cl and HNO3 in small amounts after filtering all used HCL and mixing it together. Perhaps the nitric and chlorox will be removed from the solution when heated, or the amount is so small it won't affect the process ?

What could be the possible implications when using HCL with traces of nitric and bleach?

I realy want to know as much as possible before i try it, I already messed up some recovery's...

 

[patnor1011]

Sand method for motherboards will be very bad choice. Unless you take out every bit of plastic and rubber. While sand is good and much preferred for ram sticks compared to what you want to do, processing motherboards is better to be done with hot air - heat gun.

What may look like short-cut may leave you with much more time spent at the end. I processed many hundred kilograms of ram sticks and boards and would not consider doing them in HCl or AP. It is not worth my time. No matter how you look at it, sand method on ram is much faster than using acid. You will be lest with clean, sorted material. There will be no need processing a lot sludge and acid with array of dissolved metal.
Recovery from electronics when done as a hobby is very time and labour intensive, and most of the time elbow grease is the most valuable addition to speed up process.

 

[Bluebloomer]

Thank you Patnor for your input.

So you're saying that it's a lazy method, giving you more work in the end ?

My hands are giving me trouble as the carpal tunnel is getting worse, so playing around with the chisel isn't much of an option anymore. I could get surgery for it, but I hear many people regretting getting surgery as the problems comes back later, and the problem might get worse..

If I was to use the sand bath method for ram sticks, wouldn't many of the small mmlc just fall off in the sand as many of the ram sticks are double sided ? I'm looking for the most ergonomic solution, and not just a quick fix so your input is apreciated as you guys have way more experience than I do.

Regarding the motherboards; they have already been stripped of plastics, capacitors (electrolyte, monolithic and tantalum) and other useless items. The only items that remain on the boards are the flatpacks, other chips, cpu sockets, and the gold plated pins. Because I didn't know what the best method would be to strip them further, I just put them aside, around 10 boxes filled with 18-25 boards per box.
I bought a small reflow device, that gets up to 842 degrees F but the surface area of the heat is too small, too concentrated on a small spot, so I would have to buy a heatgun but most heatguns (perhaps all) are over a 1000 watts, and to me that's overkill. The cheapest paintstripper is around 45 dollar, using 1200 Watt.
If you guys say that it's the best option, then I will just buy one and make it work.

 

[patnor1011]

Thank you Patnor for your input.

So you're saying that it's a lazy method, giving you more work in the end ?

I would not say lazy, it just leave you with sludge and plenty of acid (guys said enough about this in earlier responses) which is really pain to sort out. It will involve several processes and multiple steps where many things may go south. I believe that it involve much more work than simply place item in a hot sand and collect it minute later. I used baking tray and when I layed in last stick I was able to put first one and it was done. That mean you can pretty much work continuously and quite fast.

My hands are giving me trouble as the carpal tunnel is getting worse, so playing around with the chisel isn't much of an option anymore. I could get surgery for it, but I hear many people regretting getting surgery as the problems comes back later, and the problem might get worse..

Sorry to hear about that. Think about it this way. There were days when I thought I have to do more and fast and pile of materiial seemed to be growing but unless you do have some steady stream of a lot of material your several pounds of ram may look a lot right now but in a few days you may find yourself with nothing to do. It is nice to be able to do a lot but it is exactly that when people try too hard, they tend to make mistakes. My experience is that "better safe than sorry" may be also used like "better slow than sorry".

If I was to use the sand bath method for ram sticks, wouldn't many of the small mmlc just fall off in the sand as many of the ram sticks are double sided ? I'm looking for the most ergonomic solution, and not just a quick fix so your input is apreciated as you guys have way more experience than I do.

And this is exactly what we want to do. We want them to just fall to sand, collecting them by using sieve when sand cool is much easier than using chisel. I chiselled about 2 kilograms of them and I still remember how my hands and wrist felt after that. Not to mention it took countless many hours of work. Ceramic capacitors go off quite easy compared to resistors which are a pain in the ass to scrape off board. But they do contain silver and quite a lot. Hot sand is a way to sort them out fast.

Regarding the motherboards; they have already been stripped of plastics, capacitors (electrolyte, monolithic and tantalum) and other useless items. The only items that remain on the boards are the flatpacks, other chips, cpu sockets, and the gold plated pins. Because I didn't know what the best method would be to strip them further, I just put them aside, around 10 boxes filled with 18-25 boards per box.

Put them upside down, use heat gun on back side, move hot air flow slowly do not concentrate on one spot only for too long - do not overheat as smell is horrible when board start smoking. With light tap let the gravity work and pins will be falling out.

I bought a small reflow device, that gets up to 842 degrees F but the surface area of the heat is too small, too concentrated on a small spot, so I would have to buy a heatgun but most heatguns (perhaps all) are over a 1000 watts, and to me that's overkill. The cheapest paintstripper is around 45 dollar, using 1200 Watt.
If you guys say that it's the best option, then I will just buy one and make it work.

I believe they do have different bits which can be applied to the end so air flow may be spread to larger or wider area. My gun take about a minute to warm solder enough for pins to pop out.

 

[MarcoP]

So you are saying that with the acid method you wind up with a solution with traces of PD/PT/AG/AU in solution?

No, in normal conditions values will be found in the sludge as chlorides or in solid form.

I've also forgot to add that I've tried the heatgun method and in most cases I still prefer the sand bath even on motherboards.
I use a rectangular recycled pizza tray and it works great, heat fast and big enough for every board I've used so far.

Patnor gave you lot of hints on how to speed up the process, but in my case I didn't like the solder falling off from the board going straight on top the removed parts. However if you get good at it you will eliminate that problem.

Its all subjective here, try your self and then decide which one you prefer the most.

 

[Bluebloomer]

I used baking tray and when I layed in last stick I was able to put first one and it was done. That mean you can pretty much work continuously and quite fast.

I've seen youtube clips where they did the same with cellphone boards, so you've convinced me, just have to wait until spring to do so. What sand would you advice ? Silversand ?

I chiselled about 2 kilograms of them and I still remember how my hands and wrist felt after that.

And I thought I was giving up too fast hehe, don't forget the biceps I still feel them, and I've also done about 1,5 - 2 kg so far, but no more lol..

do not overheat as smell is horrible when board start smoking. With light tap let the gravity work and pins will be falling out.

Smell is horrible indeed ! Made the mistake of thinking I could pull it off with a small burner, big mistake ! Only downside I noticed then was the drops of solder that fell on the parts, but maybe it got to hot for the solder to fall ?

I believe they do have different bits which can be applied to the end so air flow may be spread to larger or wider area.

Indeed it does, the largest is about an inch or so, for chips it's perfect, flatpacks come right off. But for pins it's difficult to heat a larger area enough so all pins come off. Tried it, but by the time the pins on the left came off, the pins on the right got stuck again..

I don't know what tools you have in the USA but outhere the paintstrippers, or heatguns are most often around 1200 watts or more, to me that's overkill they used to be around 500 watt or so, wich still is a lot if you ask me.

MarcoP:

No, in normal conditions values will be found in the sludge as chlorides or in solid form.

I see, should of realized that. But thank you.

Seems like I have to do some experimenting on what works best for me with a sandbath. But after reading yours and Patnors posts I am convinced it is indeed the better way.

For the motherboards I might just buy a small heatgun to experiment with, I could always drop the parts in water eliminating the solder drops on the parts.

So thank you all again for the wonderfull advice you gave me all. Feels good to ask first instead of experimenting and then have questions on how to deal with the mess... :roll:

 

[Barren Realms 007]

This does a good job. You can get them at Home Depot.

 

[Pantherlikher]

Bluebloomer...
One of your waste acid questions...you mentioned what if HCL and Clorox and Nitric were mixed...
You would make AR which will dissolve everything...

I make it a habit to keep Nitric and AR in a separate waste process from any HCL, AP, etc.
The end may be the same but getting there might make for headaches.

B.S.

 

[Bluebloomer]

This does a good job. You can get them at Home Depot.

Wish we had a Home Depot, I'm from the Netherlands.. The cheapest heatgun I can find is this one:

It's 1600 watt and costs 23 dollar with 8 dollar shipping.

You would make AR which will dissolve everything...

I put those acids together to neutralize and throw away untill I realized they could be put to use again. So I heated the HCL on low heat for about 4 hours (not boiling) to evaporate and kill the nitric acid and chlorox, but I bet there are still some traces of it in the acid. It will perhaps not be enough to dissolve metals as AR, but I was more wondering what effect it might have on precipitation of the metals, and settling of the precipitated metals and salts.

Since then I kept all acid waste separate. No more stupid mistakes like this, they are too costley...

 

[g_axelsson]

There is no way to "kill the nitric" by heating the solution that lets you keep the HCl in solution. To denox a solution you evaporate most of the solution and add new HCl until the nitric is gone. It will take several times over of HCL than you ever had so it's a loosing proposition.

Use a heat gun with temperature control for desoldering to keep down the fumes and watch out for exploding electrolytic capacitors.

Göran

 

[MarcoP]

I've modified a tool that came with my heatgun to use it as spatula, concentrate the heat and it can also be used to push pins down. It have greatly reduced the recovery time! Hope it helps others.

 

[Harold_V]

There is generally a touch of copper left in my solution when I do this procedure.

That's because you haven't allowed enough time for the copper to cement. You can ensure full extraction by having a large presence of iron (scrap steel). The more you use, the faster will be the extraction.

I used to discard my solution on a daily basis, totally devoid of copper. You can tell when that is the case, as a thin film of iron oxide will be found floating on the surface. A quick test with a drop of ammonium hydroxide is also a good indicator. No blue reaction upon the addition of the ammonia to a drop (use a spot plate) will be a conclusive test.

You can even remove nickel, although it is slow to cement. The ammonium hydroxide test, along with a drop of DMG will determine if you have removed nickel.

Harold

 

[Barren Realms 007]

There is generally a touch of copper left in my solution when I do this procedure.

That's because you haven't allowed enough time for the copper to cement. You can ensure full extraction by having a large presence of iron (scrap steel). The more you use, the faster will be the extraction.

I used to discard my solution on a daily basis, totally devoid of copper. You can tell when that is the case, as a thin film of iron oxide will be found floating on the surface. A quick test with a drop of ammonium hydroxide is also a good indicator. No blue reaction upon the addition of the ammonia to a drop (use a spot plate) will be a conclusive test.

You can even remove nickel, although it is slow to cement. The ammonium hydroxide test, along with a drop of DMG will determine if you have removed nickel.

Harold

I left some copper in the solution to be able to reuse the solution.

If I'm doing Karat or gold filled I use new solution's. If I'm working with electronic scrap I try to reuse solution's to save costs when possible.