# 1st time - DDR RAM fingers and AP solution



## jaminking (Sep 21, 2019)

Hi all, 

I have been reading (alot), watching (alot) and making notes on PM recovery from ewaste so thought I would share the results of a first timer.

I am in the UK so materials are not so easy to get hold of than in other parts of the world. Also this is just an interest to me, not looking for profit, just something small and shiny in my hand at the end (-:

I had 250 DDR2 RAM boards (512MB and 1GB) and cut the fingers off with a pair of tin snips. This gave 300g of gold fingers (1.2g per board).
I also had 40 PCIe graphics cards and cut the fingers. These gave 100g of gold fingers (2.5g per card).

I am depopulating the BGA chips for later processing via different methods.

So total of 400g of gold fingers.




I then added 500ml of 35% HCL, added 200ml of 3% H2O2 and mixed (all outside with gloves / mask etc)




After 4 hours the liquid was a dark green with a few foils floating and a few bubbles produced when stirred




After 15 hours (next morning) a slightly darker green, more foils but no bubbles




I have a bubbler but running it outside is a concern and will need some protection. Will set that up tomorrow. I will also test with a drop of water to see if the HCL is saturated (white cloud) and add another 100ml if it is. 

Any comments, pointers or tips most welcome, I am learning and still reading and very open to suggestions.

I will update this post as things progress.

Thanks,
James.


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## glorycloud (Sep 21, 2019)

Time.

Doing gold fingers in AP (acid peroxide) takes time. Be patient.
Add a little HCL as needed. Agitating the solution (stirring) helps
loosen the foils. Some use air bubblers which helps decrease the
time it takes to get the foils to release from the boards. 

You are on the right path. 8)


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## jaminking (Sep 28, 2019)

Thanks glorycloud, after 8 days I have learnt:

1/ 400g of fingers in a 1l vessel is way too much, should have done 100g max to allow HCL to get to all the fingers
2/ with 400g of fingers the HCL saturates really quickly requiring more attention
3/ really need a bubbler to get more oxygen in to the solution

I have refreshed the HCL and will run this for a week to (hopefully) finish the experiment them do a 100g batch with bubbler to see the difference. 

James.


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## nickvc (Sep 29, 2019)

As with most chemical reactions agitation is the key, if you add a bubbler it moves the solution around constantly allowing fresh solution to attack the copper even the stuff covered by other fingers.


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## glorycloud (Sep 29, 2019)

I use a container in a container method for processing the gold fingers.
Basically, that involves a smaller plastic container with holes drilled
in it inside a larger plastic container. The agitation comes when I lift
the small perforated container from the bigger bottom container.

I don't yank it straight up but I do lift it with enough force to let the
AP solution flow out of the bottom of the perforated inner container.
Slow lift up and slow put back helps loosen the gold foils off of the
finger boards. It also allows me to shake the fingers in the small container
before I lower them back down into the AP solution so that the fingers
get moved around and foils that have been covered up are now exposed 
to the AP solution.

I like to run multiple five pound batches of fingers at a time, so I sized
my plastic containers accordingly. That also includes an even larger plastic
tub that I use for vigorously washing off the finger boards when the AP
solution has loosened the foils until the finger boards are almost foil free.
All the foils that I collect from filtering the AP solution and the water
washing tub all go into one plastic bucket that I will use to let the foils
soak in fresh HCL as a pre-cleaning process before I dissolve all the foils
at one time using HCL and additions of bleach.

All this was learned and works for me from the tutelage of many fine
forum members and from LazerSteve's videos. 8)


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## jaminking (Oct 2, 2019)

So I have had to pack away the outdoor lab due to weather and strained / filtered the AP before putting it somewhere safe. I estimate 80% of the RAM foils have now seperared. I have cleaned with water and will do the washes / AR / drop when there is a break in the rain (June 2020?!?). Until then I have this to look at which is quite pleasing (-:


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## glorycloud (Oct 2, 2019)

At this stage, I normally do washes in HCL first. Just covering the 
foils enough to let them soak for a half hour or so before I filter
them and let the base metals that are now in solution strain through
into the waste acid bucket.

I would do this two or three times and the foils get to looking nice and
shiny before I would dissolve them using the HCL / bleach method.

Have fun! You will be holding a nice shiny Au button before long! :G


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## jaminking (Nov 26, 2019)

Just to follow up on this:

I processed another 200g of fingers in the used AP and fresh HCL. The foils added to the previous and washed with boiling water, then HCL a few times. Total amount of fingers was 600g. Total weight of foils and board dust etc 8g




Ran poor mans AR at 1/10th of Hooks recipe (50ml H2O, 100ml HCL, 21g KNO3 @ 60c). 

I added the KNO3 in 2g increments every 2 minutes up to 14g then stopped as all the visible gold had dissolved. I left it on the heat for a further 15 minutes to make sure.




Let cool and added 13g of Sulphamic Acid in 3g stages, the last one was probably unnecessary. 

Now it is filtering using a charmin plug, this is so much better than normal filter paper. 







Tomorrow is checking the Ph again then a drop with SMB (-:


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## anachronism (Nov 26, 2019)

Looks OK. Do remember that the weights of foils etc are likely to be irrelevant. You're going to achieve around 4g gold per Kg of clean cut edges.


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## kernels (Nov 26, 2019)

Cool, looks like a pretty reasonable first try. I would be using around 5g of SMB on 600g of fingers. Have never checked the pH of the pregnant solution, not sure what that will tell you. You should be expecting around 2.4g of Gold, which is a nice amount to work with.


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## kernels (Nov 26, 2019)

Also, the SMB will release SO2 when reacting with the HCl in your pregnant solution, do this outside, in a breeze and don't breathe in the fumes!


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## jaminking (Nov 26, 2019)

Thanks all, do you have a preference for adding SMB dry or dissolved?


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## Shark (Nov 26, 2019)

I prefer dissolved, but that is not set in stone. Often it is determined by how clean the solution appears to me.

Nice work and it is good to see your steps working through the process.


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## kernels (Nov 26, 2019)

I always do the SMB dissolved, also, stir your pregnant solution, then remove the stirring rod when you slowly-ish add the dissolved SMB, otherwise Gold will "crystalize" on your stirring rod, once the bulk of the solution changes colour, you can stir again.


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## anachronism (Nov 27, 2019)

An I add it in lumps having let it set solid ;-)

Hehe sorry Shark and Kernels. I just had to be different I guess lads. :lol: :lol: 

Jon


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## Shark (Nov 27, 2019)

anachronism said:


> An I add it in lumps having let it set solid ;-)
> 
> *Hehe sorry Shark and Kernels. I just had to be different I guess lads.* :lol: :lol:
> 
> Jon



I would be more surprised if you didn't act different, :lol: 
But even you have to admit you have used it dissolved as well, 


For the OP, following kernels advice will get you there also, I just like to give Jon a hard time.


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## anachronism (Nov 27, 2019)

Hehe shark too right in the past I have dissolved it. I'm happy to agree with you. 

That given if you have 100g in a 2 litre solution you literally cannot afford the waste generated by dissolving it and pouring it in.


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## Shark (Nov 27, 2019)

As I said, it is not set in stone,  

I have been working on cleaning up my waste recently and I can see that point very well.


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## jaminking (Nov 28, 2019)

Dissolved 5g of SMB, a pleasing change in colour, allowed to settle, siphoned off clear water, washed 3 times with boiling water and allowed to dry. HCL washes to come at the weekend.

The glass is 26.69 so 2.56g of gold! Very happy to have got this far with all my fingers intact etc.




Thanks all for the help and pointers. I have leanrt a very important lesson from this forum and the Facebook group - Read and follow the instructions to the letter, no shortcuts - it works!


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## Shark (Nov 28, 2019)

I alternate between water and hydrochloric acid for washing, using heat. I also watch for a color change in the wash chemicals/water more than just doing 2 or 3 washes. Any color or cloudiness gets a longer wash and repeated until they stay perfectly clear. You will see the color of your gold begin to become lighter in color as well and it will become even lighter in color as you dry it.

Looking good, waiting to see the progress report.


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## butcher (Nov 28, 2019)

Also as the gold gets cleaner it will also settle much faster.


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## kernels (Nov 28, 2019)

Since your Gold came from only foils, it was probably reasonably clean to start with and would have settled pretty well. Assuming you did a few washes, you probably have above 98% purity there very easily, probably more like 99.5% + 

The washing that butcher describes becomes much more important when you recover Gold from 'dirtier' sources, where you have more base metals in the solution with the Gold. 

Well done though, it is always nice to see someone just follow the process and get the result, it is astounding the number of people who do it for the first time, but decide to change the process along the way ?!?!

Now, you will probably want to be melting it into a little Gold BB, this video -> https://www.youtube.com/watch?v=3GP6h7sCtiY&t=1s gives a decent overview, although it doesn't have to take anywhere near that long.


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## jaminking (Nov 30, 2019)

Thank you all, 

I am thinking about leaving it as powder for a while. I only have a 1300c butane torch and by the looks of it will struggle so will get a MAPP torch after christmas. I will hopefully have a little rack full of test tubes of powders when I eventually get a torch (-:


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