Sciencemadness Discussion Board

Poor man Platinum anode.

langevin - 30-6-2011 at 03:15

I would share experiment made with hard drive platter.
I read somewhere that platter are made from a cheap metal substrat coated with a thin layer of platinum.
The idea was...: Why don't try to dissolve the substrate for recover the thin film of platinum and make an platinum sticked anode on a plastic substrat?
I made a cell in which i place the platter as anode and a spoon as cathode. The electrolyte was NaCl i used 5V computer power supply. The current was 7 A . 8 hours later the cell was filled with a strange slurry withe/grey. I think thas was Al or Zn chloride or else... But no matter I discarded the liquid leaving two thin disks of "platinum" that came out in one piece .I agree they was thin... even very thin . but of platinum. I checked conductivity and it was quite good ( less 2 Ohms in the diameter )
I decided to stick them on a sheet of plastic for rigidify the whole and cut arround the platinum disks and join them with wire coated with silicon
I made another cell with this anode and a spoon as cathode always the same voltage/current/electrolyte.
It ran for 50 hours approximately until today.
Some cristals appeared in the bottom of the cell . I plan to keep it running until dead.... to see how last it can work.
I don't have pics ou vids yet. The result seems to me encouraging
I'll post when i have more data.
Please be lenient for my poor english language.

cyanureeves - 30-6-2011 at 04:33

you mixpelled the word I. just kidding. you dissolved the aluminum inside the disk just like that kid on youtube dissolves the zinc inside pennies and leaves the copper skin you think you have chlorate on the bottom?i only made hypochlorite when i tried to make chlorate with salt. i also made about 2lbs. of rust when the chlorine fumes got to all my snap-on tools and tool box.very cool! i just used a disk to cap a gold chlorine solution and it ate away the first outer layer which was a gold tone color. they were off a gateway said you dont have pics yet? that means soon you always make things clearer to explain. i hope it works.

unionised - 30-6-2011 at 12:15

Why would they use platinum in disk drives?

condennnsa - 30-6-2011 at 12:42

Well if it's true, and it really works for an anode, this would be a most amazing discovery for amateure electrolytic (per)chlorates...
I googled a bit and it seems that HDD platters are indeed coated with a thin layer of Pt and something alloy:

weldit - 30-6-2011 at 13:01

There is no platinum in hard drive platters. I know you can read all over the net about how to obtain the platinum but it is false. I have tried and done much research. At the scrap yards and electronic salvage yards where precious metals are extracted from electronics the old hard drives are either reused or scrapped as dirty aluminum. The thin film is mostly chromium. If you dont believe me go ahead, but think about this. If there is platinum why are harddrives so cheap.

LanthanumK - 30-6-2011 at 13:29

I electrolyzed a hard disk platter and the inside was eaten away. The inside was Al metal. The shiny surface did not dissolve electrolytically. Instead, it coated my Al(OH)3 with flecks of metal. I doubt platinum is in them, but some of them do have small amounts of dysprosium.

condennnsa - 30-6-2011 at 13:32

Platinum is used in the production of hard disk drive coatings and fiber optic cables. The increasing number of personal computers will have a positive effect on platinum demand in the future.

The hard drive is the component of the computer where data is stored. Each drive contains one or more platters or disks where data is stored on the magnetic surfaces. The amount of data that can be recorded on a given surface depends very much on the strength of the magnetic field generated by the surface layer.

Back in 1957 when IBM first introduced the hard disk, storing just 5 megabytes of data require fifty disks, each measuring 24 inches in diameter. Fifty years later, a much smaller 3.5 inch disk drive is capable of storing over 500 gigabytes of data. An important process to achieving this remarkable increase in storage capacity is by adding platinum to the cobalt alloy to enhance its magnetic properties, allowing data to be stored at higher densities.

With so much digital content being created (at higher and higher definitions) and then shared online by millions of people over high speed broadband internet, the strong demand for higher capacity disk drives has resulted in more platinum being used in the manufacture of hard disks to enhance their storage capacity. The proportion of platinum in the magnetic alloy has gone up from less than 10 percent in 2002 to 35 percent in 2007.

This is from a another website about platinum uses.

New HDDs aren't cheap.
I found one figure which states that the actual Pt alloy coating on the platters is 30nm.
If it's Pt 10-35% then that's a few miligrams of Pt per platter. That's a few cents' worth.
So the Pt price argument is irrelevant since it is supposed to be present in very very small amounts.

LanthanumK - 30-6-2011 at 15:02

If it is just an alloy, can it really be used as a "poor man platinum anode"?

langevin - 1-7-2011 at 01:14

May be the title of my subject was wrong....
Better could be : Poor man "suitable noble metal" anode for chlorate producing.
In fact i don't know if the metal recovered from the platter is Pt.
I just read some sites that was Pt.
All i can say is it run for 70 hours . I noticed a small reduction of the current ( currently 6.5 A) may be announcing the end ...
There is small amount of cristals in the bottom of the cell . I'll wait the death of my anode for dry them and proceed a test
Also . The goal of my experiment is not to recover Pt for sale but just make convenient and cheap anode for making chlorate .Thanks

hissingnoise - 1-7-2011 at 02:59

The goal of my experiment is not to recover Pt for sale but just make convenient and cheap anode for making chlorate.

Use cheap, convenient graphite anodes if chlorate is what you're after.
And NaClO<sub>3</sub> will disproportionate above its melting point, to produce chloride and perchlorate . . .
These can easily be separated by fractional crystallisation!