# Initial Platter Testing



## lazersteve (Oct 23, 2007)

All,

I've processed a single hard drive platter and came up with some numbers and an unexpected result. 

First the numbers:

Platter pretreatment weight *14.65 g*







The platter was shiny silver like a mirror, not the brown type.

Platter weight after 24 hours in cold 70% nitiric *5.75 g*






Foils weight after 32% HCl treatment *0.40 g*





[img:571:533]http://www.goldrecovery.us/images/platter_vial.jpg[/img]

*Foils in hot 70% nitirc.*






Rinsed foils after hot 70% nitirc treatment *<0.05 g (limit of scales).*














The shocking results of this experiment are as follows:
*Fresh stannous chloride shows NO coloring hint of platinum in the tests as seen here: *






*and a comparison of the liquids extracted from the foils with hot AR verses liquid from palladium bearing monolithic capacitors. The AR foils test tube is on the left and the test tube of monolithic capacitors on the right is known to contain Palladium:*

[img:502:335]http://www.goldrecovery.us/images/platter_testtubes.jpg[/img]

After these odd(?) results I wanted to determine if the amount of Platinum was too small to detect so I processed a few catalytic converter beads as a baseline test. The results were pretty conclusive as to the power of stannous chloride to detect traces of Platinum as seen here:

First the beads after boiling 5 minutes in AR:






and finally the stannous chloride test of the bead solution:






From these tests I can only conclude the platter I tested had no Platinum content. 

Has any member ever processed a platter and verified the material produced was indeed Platinum? If so please post evidence of your experiments so we can compare the processes.

I've saved all the left over solutions and they test positive for Cobalt, and negative for PGMs.

Steve


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## jimdoc (Oct 23, 2007)

Steve,
I haven't processed any, but I have read somewhere that they contain platinum from about '97 on and on 20gig or higher hard drives. It is
possible that some don't contain any platinum at all. I know we don't want to hear that. You should try a known newer disc and see what you get.
Also like you said the amount may be way too small to measure from certain single discs. Most of the computers I get are probably older than '97 so the hundreds of platters I have may not be worth anything.
Jim


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## lazersteve (Oct 23, 2007)

Jim,

I'm going to concentrate the solution in the test tube and see if it tests positive after that. If not I'll try a newer platter. I have plenty of dead 80 gig drives on hand and even a few dead 200 gigs.

If the amount is so small that it doesn't show up in concentrated solutions then platters may not be worth processing for the minute traces they contain.

I'll update this post later. I have plenty of scrap that is producing PGMs and don't want to waste time and chemicals on ones with little to no PGM scrap value.

Steve


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## Irons (Oct 24, 2007)

How about doing a spot test on the platter before you waste time removing it from the drive?

Taking the cover off the drive is a simple procedure.

You have to figure in labor. Once you know what manufacturer and size contain PGM's, then it's all about sorting.


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## lazersteve (Oct 24, 2007)

Irons,

I tried that prior to this test and the surface resisted the test chemicals. I tried acid pretreatment of the surface with no results either. After that I decided to process a single platter to get the results you see above. 

I believe the foil coating has some type of organic bonding material that makes the direct test methods you mentioned nearly impossible.

This is why I proceeded to destructive testing.

Steve


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## Irons (Oct 24, 2007)

A three atom thick layer of Ruthenium is some mighty slim pickins'.

http://en.wikipedia.org/wiki/Hard_disk

-snip-

The platters are made from a non-magnetic material, usually glass or aluminum, and are coated with a thin layer of magnetic material. Older disks used iron(III) oxide as the magnetic material, but current disks use a cobalt-based alloy.

--snip--


n modern drives, the small size of the magnetic regions creates the danger that their magnetic state be lost because of thermal effects. To counter this, the platters are coated with two parallel magnetic layers, separated by a 3-atom-thick layer of the non-magnetic element ruthenium, and the two layers are magnetized in opposite orientation, thus reinforcing each other.[5] Another technology used to overcome thermal effects to allow greater recording densities is perpendicular recording, which has been used in some hard drives as of 2006.


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## lazersteve (Oct 24, 2007)

I broke down and disassembled a dead 185 gb drive and scratched the surface thru the foil layer with a sharp knife. I treated the spot with 1 drop of 70% nitirc and three drops of 32% HCl. After 10 seconds heating and a drop of stannous here are the results:

[img:868:483]http://www.goldrecovery.us/images/185_pt_test.jpg[/img]

and a close up of the swab:

[img:740:540]http://www.goldrecovery.us/images/185_test_closeup.jpg[/img]

It looks positive for Pt.

I'll check some smaller capacity drive platters and see if I can find out where the cutoff point is....


Steve


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## Irons (Oct 24, 2007)

An IBM Death Star. lol


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## badastro (Oct 24, 2007)

Try processing newer laptop drives. They are glass and the coating is unbelievably resistant to hot aqua regia.


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## Irons (Oct 24, 2007)

First you get an Elephant.....


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## cking (Dec 18, 2007)

I'm new here - but I'm here for a reason  I have hundreds of these platters (mid-2003 and newer) SCSI drives (out of RAID systems) - so, I've got some real curiosity going on here! Any update as to the recoverability of these platters? Also, has anyone done any recovery of platinum through the ICs?
Thanks,
Chris


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## aflacglobal (Dec 18, 2007)

Welcome to the forum. :wink:


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## cking (Dec 19, 2007)

Thank you,
I've been scouring the net for quite a while now - and this site is quite the paradise in a hot dry desert. I can only attribute the dearth of information by what one site observed in an old saying - "the refiner is the last liar". Hmmm... what does that tell you about human nature? So, therein lies my quest - to learn, validate, and qualify/quantify as best as I can. So I'll know, as I accumulate old and new things/components and knowledge - what their potential worth might be. Ahhh me, yet another question for knowledge. I'm a computer analyst/admin/programmer/researcher/site admin/pseudo web developer/wannabe graphics artist/reader of books/dad of soon to be 3/computer repair technician/wood working hobbyist/tinkerer of electronics/and now, if I just didn't care to not know the truth about things, then I'd probably just drop this whole mess - but I just... can't... stand... to not know... you could say - it's largely what drive me.
Anyways, there also this book called 'acres of diamonds'... it's a great read about what people did with what they had... instead of complaining or pining about some far away dream. So...
Anybody got any yield data on platter recovery?


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## aflacglobal (Dec 19, 2007)

> I'm a computer analyst/admin/programmer/researcher/site admin/pseudo web developer/wannabe graphics artist/reader of books/dad of soon to be 3/computer repair technician/wood working hobbyist/tinkerer of electronics/and now,


  

Sounds like one of my resumes. lol


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## aflacglobal (Dec 19, 2007)

> dad of soon to be 3



Now that's cool. :wink:


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## Lou (Dec 19, 2007)

Steve, did you ever get a PGM yield per kilogram of platters?

I have about 400 or so old hard drives and at least that many motherboards and corresponding memory cards that a friend has offered me. I'm wondering if it's worthwhile to go after the platinum on those platters?


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## lazersteve (Dec 19, 2007)

Lou,

So far I've only found a few platters that are even canidates for Pt recovery. 

I'm filming the processing of them on my new DVD, but have not dropped any Pt from the liquid yet. 

Christmas has got me going in too many directions to put any real time in on the DVD project.

I'm very skeptical that the yields will warrant the effort. Just looking at my preliminary findings of <0.05 grams of nitric insoluble foil per platter is discouraging to say the least. 

The first order of business with your platters will be a quick scratch and stannous test. I'm finding that most silver colored platters don't even show positive for Pt.  

Steve


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