Please be sure to read my info on platinum recovery and refining from scrap hard drives.
I have been experimenting with different types of computer scrap, including HDDs, or hard disk drives. Hard drives are an impressive feat of computer, mechanical, and materials engineering; And as far as I’m concerned, engineering in general. Hard drives are composed of several main components, namely the magnetic actuator, the small write head, the platinum-plated aluminum platters, the circuit boards, a small motor, an aluminum block, and a stainless steel cover.
Just like a CD/DVD drive, the hard drive has a precision logic board/circuit board that handles all the i/o and information processing in the drive. These circuit boards use high value metals like palladium and gold in their construction.
The logic boards off a scrap hard drive are considered a premium grade of circuit board scrap. They are worth more than computer motherboards because they are more densely packed with trace amounts of precious metals (parts per million).
|A disassembled hard drive showing the platinum alloy plated platters, the neodymium
magnet bracket in the top right, the aluminum case, and the stainless steel cover on the left.
I first became interested in hard drives when I disassembled one to harvest its super magnets. These magnets are made of a standard neodymium iron boron composite (NdFeB). Neodymium is a rare earth metal that corrodes rather quickly. To fix this, the magnets are plated with nickel.
|Because NdFeB magnets corrode in air fairly quickly,
nickel is electroplated onto the magnet and bracket.
These magnets are quite powerful, almost dangerous if they are strong enough. This poses a threat to computers, seeing as most data is magnetically sensitive (at least to some degree). To combat this problem, computer engineers make the magnet’s brackets out of an IRON, NICKEL and MOLYBDENUM based alloy called a permalloy! Permalloy has an extremely high magnetic permittivity, meaning it will stop most magnetic fields.
I have started collecting the individual hard drive components, seeing as they are worth quite a bit more individually then as shred steel! I have a box that I put the aluminum base, the supermagnets and brackets, and the stainless steel covers.
Last I checked, I could get a little more than copper price for my permalloy brackets. I shopped around at some of the bigger yards, but they thought it was too small of a amount to be worth their time. At the family owned place near me, I can get over $3 per pound for the brackets.
If you are considering harvesting the platinum from the hard drive platters, GOOD LUCK; The coating is atoms thick, and is at most 40% platinum ALLOY. I have had some questions regarding refining this platinum coating, and I can assure you it is not lucrative unless you have TONNES of hard drives. We are talking platinum in the parts per billion. For more info, check out http://www.goldrefiningforum.com/
More recently I have learned that artists will buy these old hard drives for use in crafts and projects; the coolest of which I have seen is this clock:
10,000 rpm. Learn more here.