# Hard Disk Platter Removal: Questions/ Comments



## lazersteve (Apr 6, 2007)

This is where you can comment on the Hard Disk Platter Removal Tutorial

http://goldrefiningforum.com/phpBB3/viewtopic.php?p=1777#1777

Steve


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## Fever (Apr 6, 2007)

Nice demo, Steve.

About the only thing I can add is that there is good scrap metal values in the drive bodies themselves. They are usually either cast aluminum, or pressed aluminum sheet, both of which should bring around .80 per pound at today's scrap prices. These scrap metal prices vary according to the market, like everything else, so if the current price is low, hang on to the bodies until it goes up then turn them in for scrap. The older brown colored discs without Pt are aluminum as well, and can be recycled along with the bodies.

I'm looking forward to a future episode of you doing the acid digestions and refinement of the Pt alloy flake!

Fever


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## lazersteve (Apr 6, 2007)

Fever,
You are correct about the housings. A few rare ones are cast magnesium believe it or not. As I've said before, I don't throw anything out. The way I figure it is waste not want not.

If more members express interest in this topic I'll work on the processing portion. I never put any of the disk thru the refining process so it would be a learning experience for me as well. 

It seems only a very few of the members are actually getting involved in any of the dialogue for whatever reason. I would like to encourage any of the newbies, experienced or not to make a post of some sort, a new topic, a question, or just a comment if nothing else.

Steve


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## Fever (Apr 6, 2007)

Agreed! It's important to keep the dialog flowing! :!: 

I think there would be strong interest in seeing you perform the digestions on the discs. As I posted earlier, with the price of Pt around $1200/oz. I can't imagine why more people would not want to consider this resource in their scrapping agendas......

Fever


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## Fever (Apr 6, 2007)

For those who could not make out the fine details in the differences between the silvery Pt-containing discs, and the brownish-red discs with no Pt, here is a shot of the two for comparison.

Fever


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## lazersteve (Apr 6, 2007)

Here's a previous post of the same info:

http://goldrefiningforum.com/phpBB3/viewtopic.php?p=966&highlight=#966

Steve


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## bermudanibiru999 (Apr 6, 2007)

lazersteve said:


> It seems only a very few of the members are actually getting involved in any of the dialogue for whatever reason. I would like to encourage any of the newbies, experienced or not to make a post of some sort, a new topic, a question, or just a comment if nothing else.
> 
> Steve


I'm a newbie. Sorry I haven't really gotten too involved with the techniques or forum responses. But I am taking everything in. Other responsibilities have kept me from "experimenting monetarily" (for lack of a better phrase) :? so money is kind of tight right now. But I am still learning. Recently, I purchased a shor international sub zero starter kit to help me get my foot in the door. I have about a pound of computer scrap that I'd like to refine but i'm still getting more products. I don't know about the other newbies, but I'm still here. And I appreciate this forum as well as the learnt members of this forum. Thank you so much for your expertise


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## Jackrabyt (May 8, 2007)

I for one would love to see a video on the refining/recovery process for these platters. I have a load of them and have not attempted anything with them yet.

Great job as always Steve.


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## firedan525 (May 9, 2007)

Great video. I am glad I finally got to see it, I've got a bunch of them and now know what they are. I even used the dremel trick. Pretty slick. Question= How many LB's does it take to make processing them worth while? And I am in strong agreence that I would love to learm how to recover PT out of these. Thanks again, DAN


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## Noxx (May 9, 2007)

I think you should run an HCl bath first to dissolve other base metals. Then you can refine it with the AR method.


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## Anonymous (Jun 22, 2007)

I just got to this site today and have to say most sites like this confuse me but you people here seem to be verry knolagable and explain things so even i can understand most of them. i have been wondering what to do with a few old computers and you have the answers i'm looking for. thank you for the keep up the good work. Jerry


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## lazersteve (Jun 22, 2007)

It's great to have new members learning things on their first day!

Welcome to the forum Jerry,

If you don't mind I would like to point you to a few starter links :


 Must Read

 Forum Guide Rough Draft

 Reactions List

Be sure to ask lots of questions and take photos if of your work before and after if you can.  


Oh, and try to have fun while you are here!!

Steve


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## scavenger (Jul 10, 2007)

I have over 700 hard drives most under 5gb. I stripped a few and found it real time consuming. Is it worth it?? Has anyone had experience with these that resulted in a decent haul of pt?


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## lazersteve (Jul 10, 2007)

Scavenger,

The jury is still out on this one. This process is on my list of future tutorials. Wayne, austexjwlry, has posted photos of some platters boiling in AR, but no yield data. If I recall correctly, he mentioned he sends all his Pt out to be refined. Maybe he will share his yield information with the forum.

Once I get to this tutorial topic. I will be posting my yield data for everyone to use when purchasing this type of scrap.

Steve


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## badastro (Jul 11, 2007)

I have unsuccesfully dealt with hard drive platters.

It takes about 1 pound of intact platters to yield about 40 grams of foil that does not dissolve in HCl.

To get foil, I used heavy duty shears to cut up the platters into wedges. Dilute HCl is used to eat away the aluminum. Dilute acid is important to minimize dangerous fumes and acid evaporation. It takes about a day and a lot of acid to do the job.

I noticed the newer platters (20+GB) are more silvery in color than platters around 4 GB. The newer platters are also thicker... and it seems that newer platters are made of aluminum which have some sort of particles embedded in them. When dissolving newer platters, you get the foil and black gunk from the stuff in the aluminum. I think the particles add strength to the aluminum.

I sent the 40g of material to a refiner, but I never heard from them again :evil: :x :evil: :x :evil: :x 

Later I tried a smaller batch with new HDD platters. The foil dissolves in AR to give a greenish colored liquid. I neutralized the the nitric acid with urea and added ammonium chloride, and nothing happened.  

My guess is that the concentration of platinum was too low to precipitate because ammonium chloroplatinate is slightly soluble in water. In fact, it is recommened to rinse the platinum precipitate with a saturated solution of ammonium chloride and not water.

Interestingly, the foils do not completely dissolve in hot poor man's nitric acid mixture...

Perhaps a better method would be to melt the foil with silver and use the inquartation process.

It is also worth noting that platters from laptop drives are made of glass. I have been unable to dissove the coating with hot AR, but I only had one platter and was impatient to leave it to dissolve any longer. They are extremely resistant to AR, though this may be due to low surface area for reaction.


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## Noxx (Jul 11, 2007)

Do someone know the Pt content of the foil after the platter has been dissolved in HCl ?

Thanks


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## synthetiklone (Feb 14, 2008)

Hello everyone, 

(I've just reposted this in this more suitable thread)

I must also say thank-you to the tutors and mentors starting and contributing to this forum. I too have wasted a fair amount of cpu's (gold/etc) experimenting in the past. (heh - including blowing a decent pile of gold dust clear off the fire brick because the flame was too strong!). 

I was reading in this thread about disc platters and thought I might share some info on my experiments. I delved into aluminium anodising a while back, and I used sodium hydroxide (caustic soda - an alkali) to flash clean the aluminium. It is cheap here, and available as a drain cleaner. 

Anyway.. 

I cut up all the most silver looking platters into 10mm strips using big tin snips (yes, a few blisters!) to expose the aluminium base material on the edges for easier/quicker dissolving. All was placed in a solution of sodium hydroxide in a plastic heat proof container, and it fizzes away (and initially gets quite hot) for days at room temp. A little agitation each day to keep things moving along. After a week you are left with a milky powdery goop with the thin platter plating floating around. Once filtered and cleaned, I tried to melt the foil with propane torch, with no effect, simply gets very hot, and crumbles into smaller pieces. It is quite sharp & unpliable (nickel?) 

UPDATE: I left some in room temp nitric for a day & I now have very thin shiny (pliable) foil bits floating about. The next test will be heating the nitric. And after that (or maybe before!) I will be watching lasersteves (?) video/info for more advice I guess! 

I have been collecting ceramic honeycomb from cats and oxy sensors, and CPU's, but where I live, the local recycler has a 99.9% monopoly on buying EVERYTHING available from all the collection depots around town. 

Thanks for your time, and hope I am not going down the wrong track with using alkali to dissolve the aluminium, and if not, I hope it helps others. 
I am looking forward to the "anxious newbie" part of watching the gold dissapear into AR, once I am confident enough with (not stuffing up) the process! 

Will be sharing anything new (maybe re-invented?) that I discover in the future here, but you guys/gals are currently way ahead, and more confident than I currently am. 


Cheers 

SK


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## ddrew (Feb 25, 2008)

synthetiklone said:


> All was placed in a solution of sodium hydroxide in a plastic heat proof container, and it fizzes away (and initially gets quite hot) for days at room temp. A little agitation each day to keep things moving along. After a week you are left with a milky powdery goop with the thin platter plating floating around. Once filtered and cleaned, I tried to melt the foil with propane torch, with no effect, simply gets very hot, and crumbles into smaller pieces. It is quite sharp & unpliable (nickel?)



Hey Synthetiklone, I'm interested the process using Sodium Hydroxide to remove the plating on hard disk platters. I have some powdered Sodium Hydroxide, and have a couple thousand platters that I've collected, and would like to start processing them. If you don't mind a few questions, I'd really like to 'pick your brain' and see if I can use a similar process. 

1. I presume you were using liquid sodium hydroxide, but am curious about the strength you used, and the brand of cleaner you were using.

2. After the plating was separated into a 'white goo', how did you (or plan to) separate it back to the base elements.

3. How odiferous is the process? I have some potentially cranky neighbors, and was curious if this process will cause any neighbor problems. If so, I'll have to work around that problem.

Chemistry isn't my strong suit, but I'm reading alot and learning on the fly. I've gone through the safety tutorials, and really appreciate the wealth of knowledge shared by everyone on the forum. Thanks again.


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## synthetiklone (Feb 27, 2008)

Hi, about to reply and Ive just been called out, so will edit this as soon as I get back and answer your questions...

SK


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## synthetiklone (Mar 4, 2008)

Hi again, sorry delays, been really quite busy,

I would firstly suggest you (& us/we/them/everyone) do some smaller scale experiments before you commit to doing this in bulk, as I'd hate for it to be a complete waste of time, money, and effort for you, and we end up with nothing more than some worthless white aluminium goop and a drop of nickel... :shock: Then again, we need a guinee-pig to do some platters in bulk and see if low platinum content is why its not showing up on tests. The process I describe is quite cheap, and I guess the worst part is if you are manually cutting the platters up - blister city! 

Anyway, on with the show..

I purchased it from a hardware store in NZ called Mega Mitre10, it is only NZ$5 for 500grams. Brand is Tergo Drain Unblocker - 100% sodium hydroxide. (eats aluminium but copper (plumbing & Pb?) is left unharmed)

I used a 2 liter container almost filled with warmed tap water and roughly about 50 grams of powdered sodium hydroxide.
Mix it as you pour powder in as it will cake up on the bottom, and become more troublesome to mix.
I dropped in about 10 cut up platters. Also do this outside, or with something protecting surrounding area and maybe a loose fitting lid on the container (dont seal it, as gas will build up) as while it initially fizzes away, alot of splatter exits rim of vessel for about 2 ft all around! I did not notice any odours whatsoever from this process, and without further study, I dont know what gas is emitted. (I didnt really want to get too close with my nose on this job! 

On the subject of the remaining white powdery goop (aluminium something oxide maybe? I don't know if its worth reclaiming or useful for anything, but there is a fair bit of aluminium in there)

The platter foils remain and I simply tipped off white goop, discard, rinsed & cleaned the foils in water a number of times.

These remaining foils have a shiny side, a dull side, and are quite sharp/brittle. I decided to try and refine further with 68% nitric acid. From memory, after a few days, the nitric turns blue, and the foils are reduced to a shiny powder-like dust floating in solution. Some foil bits don't dissolve down to dust size, and are still elongated.

I am wondering greatly at this stage what I am left with!

I have now also tried a similar process, but dissolving foils in aqua regia, as I would hope that everything would go into solution except the platinum, but, I accidentaly mixed aqua regia with 50% water, and nothing happened. Having no more nitric or hydrochloric, I decided to gently heat this mixture. I have written about this elsewhere on the forum, but to quickly summarise. When it got warm, it began a chain reaction, sustaining its own warm temperature & fizzing mildly away for a half hour. I was left with a lovely lime green liquid, with extremely fine silvery (colorwise) dust particles floating about. These dust particles are magnetically sensitive, with me being able to change their magnetic polarity in solution with a powerful neodymium magnet. This creats a wave of reflection in the liquid when mixed.

(NOTE: Anyone doing this, to be wary of magnets above aqua-regia solution should particles jump out. I dont think these particles are that attracted, but warning just in case)  

This is where I'm at until I get some more hydrochloric, and some tin powder to make some stannous chloride testing solution.

Also, next I am going to run a new batch using non-diluted aqua regia! :lol: 

Then, if anything is left, collect it all up, and dissolve in hot AR, and precipitate !?!?!? - one day 

I am also trying to find out (more re-search/study forum) how to drop out the (probable) nickel, just to see how much there is in solution.


Regards

SK


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## ddrew (Mar 5, 2008)

synthetiklone said:


> (NOTE: Anyone doing this, to be wary of magnets above aqua-regia solution should particles jump out. I dont think these particles are that attracted, but warning just in case)
> 
> SK



Thanks Synthetiklone for the great detail. In regards to using the magnets, is it better to extract the magnetic particles at this stage of the process or is it better to wait until the materials are in a powdered form?

Please keep us advised on your progress. I'm still removing platters from drives. I've ran into a batch that has them pressed together rather than mechanically fastened. They're a real bugger to get apart...


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## synthetiklone (Mar 6, 2008)

Hi,

No stop! - the silvery particles themselves are ALL magnetically sensitive.
I wouldn't extract them with a magnet. It is just an interesting anomaly I write about.

I would probably find out what they are, and if they resist aqua regia, try hot aqua regia, platinum is suppost to dissolve in it then, and I guess if you have enough, it might test positive! I am still a bit suspicious though, as there is quite alot of this silvery dust compared to the amount of original coating, and surely too much to be solely platinum. At least "I" don't think there is this much platinum from what I've read, it is only a small addition. 

As far as the rest of the process goes, I'm no further than where I've written about. I am in need of more nitric, and hydrochloric, not to mention some SMB and some urea, and while I'm on the subject, I've still got to find some tin powder from somewhere.

Things are progressing slow, so slow, that I've resorted to using ferric chloride to strip some pins, and after trying to dilute and rid the ferric chloride, I'm left with the gold mixed in with some light brown powdery muck at the bottom of the beaker. Bagghh it all  I now have two beakers of gold flakes in powdery muck!

I've also manually sliced the small chip wires from 50 486's, and compressed the bits into a nice little block of gold 3mm x 3mm x 2mm high.. quite impressive for just the wires. (UPDATE: I pressed them even smaller, but regretted this later as when trying to dissolve solid block in HCl/chlorox, proved time consuming!) Now to figure how to get the rest off the ceramics, and do a tally up. BTW, there is a gold plated panel under the wafer chip, looks like some form of silver solder/epoxy holds the wafer on, heat removes the wafer, unless the acid can get under it.
BTW, if you can remove the silicon wafer chips cleanly, they are of great interest to students studying microscopic things. sold quite a few now for $5 each! waste not want not.
[UPDATE: See my unusual sulphuric cell post for exp of how I ended up doing the cpu's! plus a tally up in weight of gold content for the 50 cpu's only. very interesting]

Ohh yes, also must mention in case someone misses them. In some brands of hard drives, there is a gold interconnector, the (20?) pins are 4 times the length of the IDE edge connector ones, it is located out of sight, under the PCB, joining the PCB to the internals of the drive. Well worth it. Also noted that its best to try and pull any connector pins completely out, as quite often I found, the gold goes into the plastic, and sometimes even right out the back and to the PCB. What a waste to simply clip or break it off!

Q: If complete pins and plastic are thrown into acid, as I've read some ppl do, does the acid get down inside the plastic, and does all the gold come out ok?


Regards
SK


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## lazersteve (Mar 6, 2008)

synth said:


> I am in need of more nitric, and hydrochloric, not to mention some SMB and some urea, and while I'm on the subject, I've still got to find some tin powder from somewhere.
> 
> Things are progressing slow, so slow, that I've resorted to using ferric chloride to strip some pins, and after trying to dilute and rid the ferric chloride, I'm left with the gold mixed in with some light brown powdery muck at the bottom of the beaker. Bagghh it all Smile I now have two beakers of gold flakes in powdery muck!



There is a nitric acid recipe here on the forum under the Guide to the forum that requires sodium nitrate and sulfuric acid. 

Lots of household products (driveway cleaner and pool acid) contain HCl, check the MSDS on the manufacturers websites.

SMB can be obtained from http://chemistrystore.com .

Urea isn't required, just boil down your AR solutions three or four times after dissolving your gold or use HCl-Cl instead and you won't need to boil down to remove the NOx.

Cleaning up the FeCl3 muck is easy if you have HCl. Just wash wash the foils and muck with hot 15% HCl a few times filter, rinse with plenty of water, and you are set.

The plastic headers can cause problems, some types turn to much and trap the gold.

Steve


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## synthetiklone (Mar 7, 2008)

Hi, thanks for the info, on the FeCl3 too.

BTW Steve, congrats from me too, on you doing the videos, it sure helps quantify all the writings.. like the old saying goes, "A picture is worth a thousand words". Thank you.

I am trying to watch the platinum video, but I'm on dialup, the video is long, I buffer 30 megs, then the video starts, and I loose the connection without watching 2 seconds. Is there a way of splitting it up smaller, or a way of recovering it from half way. The other ones are sweet so far. Thx. 

Ive found SMB at a home brewery supplier, and some urea at a gardening store! Ive just got to find our (NZ) equivalent of Chlorox, and hydrogen peroxide.
Fantastic stuff.. getting there, and hopefully post some button pics soon 
(I cant believe how much Au is in 486 chips, and Ive only dont the wires so far! Will post a pic of my fine-gold-wire cube when I get a chance!).

Cheers
SK


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## lazersteve (Mar 7, 2008)

The reason the videos are in a single file is for the MAC users. The split files would not play sequentially for them unless I joined them before posting. 

Steve


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