Harddrives - what can be harvested - and what it contains ?

[Lou]

Of course you can ask. If in acidic conditions, HAuCl4, potassium chloride, and HCl, not very good cosmetic deposition on Ti, to get that the deposit must be heated.
Platinum deposits clean with various salts, K2PtCl6 in HCl works on Ti. It also works with perchloric acid for other Pt salts. You can add a little lead (II) acetate to help speed it up in dilute solutions.

Otherwise, a cyanide based system, of which you should be most familiar if you've owned plating shops. Gold potassium cyanide, free cyanide, a suitable buffer, and the salt of a weak acid (i.e. ascorbate salt) with electricity, although there are other aqueous nonelectric reduction methods.

I do this for making electrodes for electrochem, mainly platinized Ti and sometimes on Ni, not for jewelry.

Now if I may ask, what did you plate, and what types of solutions did you use? I may be asking for recipes if it's not proprietary.

Regards,
Lou

 

[goldsilverpro]

Lou,

A long, long time ago, I was a senior chemist for Sel-Rex, which was, at that time, the world's largest provider of precious metals plating solutions. Among other things, I was in charge of the manufacturing of these solutions. The formulations today are essentially the same as they were back then. We sold about 200 different types of gold solutions and about 95% of these were made up with potassium gold cyanide (PGC). The rest were made from sodium gold sulfite. Platinized titanium or tantalum was used as anodes.

Unfortunately, I can't remember the exact formulas, as I haven't used them in 30 years. The most popular system we sold was a hard, bright gold that was used on such things as PCB fingers. It contained 1 tr.oz. of gold per gallon, as PGC. A small amount of nickel sulfate or cobalt sulfate was used as a hardener. The electrolyte was large amounts of potassium citrate and citric acid. I'm thinking the pH was around 4 or 5. It's been too long. The gold deposit purity ran from 99% to 99.9%, depending on how much Co or Ni was used.

 

[Lou]

Wow, it is a pleasure to talk to someone so knowledgeable and has much real world experience. You're definitely a resource. The stuff I do is very much on the small scale and most of it is for the little electrochem work I do in the laboratory.

 

[Gotrek]

I know this is an old post and sorry for bumping it. But there is also gold on the head contacts of the writing arms. Although very small it can be seen with the naked eye. Look at the head of the writing arm (the little black squares on the arm, the Copper wire is soldered to them. They are cold. I tried to break on open to see how deep the contacts are. Seems to be surface only.

 

[synthetiklone]

Hello everyone,

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

 

[aflacglobal]

Welcome to the forum synthetiklone. Glad to have you. :wink:

 

[starzfan0211]

As LazerSteve pointed out, there are lots of stuff to get. But don't miss anything. As we have been dis-assembling hard drives (most of them older) we have been throwing all the cast aluminum in one box and the other aluminum in another. Cast Aluminum is going for .65-.70 per lb here right now. We are really trying not to waste anything. And we are also gathering any brass we may find, which is a little.

 

[synthetiklone]

I have written elsewhere about an update placing dissolved platter material in aqua regia, and heating mildly to start a half hour chain reaction. Thus dissolving platter material into a fine shiny dust substance. Well here is a continuation of this experiment..

While I was working with a powerful neodymium magnet (30x30x10mm) with the ferric chloride and the CPU pins being magnetic, I found that with the platter solution nearby, it would sparkle and shine. Initially, I thought it was a reflection from the chrome coated magnet, as it was like a wave of light passing through the liquid.. but......

The very fine metallic dust from the platters is strongly affected by magnetism. The particles i have left in the lime-green aqua-regia are polarity sensitive, meaning with a powerful magnet, I am able to change the N-S direction the particles sit - in solution. And this works from about 700-800mm away from the solution!

With most particles (after a stir) sitting almost suspended, when I rotate the magnet N to S, a wave of bright light is reflected from the particles whos orientation along the magnetic flux plane is shifting. It is quite a display, and in all my long years of "pottering" about with chem & tech, I've never seen anything as intriguing. It's almost as cool as "ferro fluid".

So, there you go, whatever the hard drive platter material left unable to dissolve any further in the aqua-regia is magnetically polarity sensitive.
I will be placing some of this dust under 300x microscope to inspect its shape soon and report back if there is any interest.

Is platinum this way magnetic? or maybe, whatever it is, is bound up in the platinum? or maybe theres no platinum at all, and it is something else huh. I'll have to re-read up on the manufacture of the platters again, maybe there is mention there of composition.

Anyway, what an interesting fascinating subject, it's like "low-tech chemical reverse engineering".

Hey, BTW, is anyone reading my rambling experiments? or is all my writings already known, and I make unecessary repeats clogging/cluttering, and generally boring peoples of the forum?


Regards

SK

 

[Platdigger]

Cobalt is magnetic.

Platinum is....what's the word?.....paramagnetic?

Randy

 

[Chuck_Revised]

Yes, we're reading your texts. It's very interesting. Welcome to the forum and please continue your contributions.

 

[calgoldrecyclers]

i was reading on a computer website yesterday, that the newer platters are made of a composite glass, with a micron thick layer of ruthenmium(a pt mineral) but does not contain paltinum or any other pm. the most you could get out of a dead drive is the aluminum. it is just not proffitable to go after recycling drives.

 

[jimdoc]

Ruthenium is a precious metal worth about $420 t/oz.
It has been close to $1000 recently.
I don't know if recovering it would be worth it.

 

[Anonymous]

If the platter is aluminum, it should be possible to justify the cost of recovering any platinum group metals or anything else by converting the aluminum to high grade powder which retails for anywhere from $20 a pound to $6 a gram depending upon grade. The Pt group metals should just be gravy. Maybe? Possibly?

Nope, answered my own question. Too hard to refine into it's pure form. Forgive my ignorance, I am definitely a newb. Maybe there is some other aluminum based compound that's easily marketed?

 

[jamthe3]

how do you convert Al to high grade powder?

 

[Anonymous]

Usually they produce aluminum powder by crushing in a ball mill with stearin. If one melted the platters and the "skins" could be separated in some simple fashion the cooled metal could be pounded to dust. Hopefully, it wouldn't require refining aluminum which is a really nasty process done with molten salt.

 

[ddrew]

Usually they produce aluminum powder by crushing in a ball mill with stearin. If one melted the platters and the "skins" could be separated in some simple fashion the cooled metal could be pounded to dust. Hopefully, it wouldn't require refining aluminum which is a really nasty process done with molten salt.

I see there a market for this 'High Grade Powder' Aluminum, but I would think the alloy of the source materials would matter, but I'm not sure? Can you take scrap aluminum (hard drive cases, platters, scrap sheet aluminum, et al) and run it through a Ball Mill and make High Grade Powder?

Thanks in advance for your help.

 

[Anonymous]

This will take a bit more research. It may require heat stressing to make the aluminum friable and though the alloy does have useful properties it probably wouldn't be useful for most metallurgical processes. It would likely be fine for aluminized coatings and roofing products. One other possibility I've seen is reagent grade aluminum oxide. The technology can be learned, marketing is going to be the killer.

 

[Anonymous]

Found something on fluxing aluminum with a mixture of sodium chloride and potassium chloride. Given the similarities to demagging of aluminum it might actually produce a fairly pure metal. If anyone else knows something about this the info would be greatly appreciated.
If a pure metal could be produced it would be a matter of crushing and sorting according to particle size.

 

[synthetiklone]

Small update with unknown results

I boiled my silvery powder material from the platters. in contaminated nitric, so dont know if anything really happened in there.
So I made up some AR, and left for some days in this acid mix.
Nothing happened, so..
Boiled AR mixture for quite some time (15 minutes), outside, as brown fumes were being created. After 15 minutes, I still have my silvery powder. It did not dissolve into boiling AR solution!
I tested the solution when cool, with stannous, and only a slight brown yellowy stain visable. Hmmm..!?!

I've since rinsed clean and placed this, still magnetically sensitive silvery powder in water into a sealed test tube, and placed it away in the "round-to-it" department.

SK

 

[patnor1011]

hi to all... as far as i know that silver platres from hd contains some pd, pa but it is not worth of processing... these discs are made from nickel which is way more worth than any pa or pd on them. we recently xray few of them and thats how i know...