NEMO-Chemistry
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1559
Registered: 29-5-2016
Location: UK
Member Is Offline
Mood: No Mood
|
|
Best Vintage for HDD magnets
Reading various threads on Neodymium from HDD magnets, it looks like the composition of the magnets has changed over time.
Weeks back i mentioned a computer shop that had closed and dumped a load of gear, in the lot i managed to bring home are some old HDD's.
From the size (storage capacity) and a few of the date codes on them, it looks like i have a few from late 80's right upto around 2005.
There isnt many of them but i wondered what age HDD's have the best magnets for Neodymium? I would like to have a go at extracting some Neodymium
compounds, mainly Chloride.silphate and nitrate.
Cheers
|
|
RogueRose
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1590
Registered: 16-6-2014
Member Is Offline
|
|
last years of 5.25" HD's and the first years of 3.5" SCSI hard drives. They both had really large magnets
|
|
MrHomeScientist
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1806
Registered: 24-10-2010
Location: Flerovium
Member Is Offline
Mood: No Mood
|
|
The older they are, the more likely they are to have SmCo magnets rather than Nd. I ran into that a few times when I got excited about some very large
magnets, then dissolved them in sulfuric acid only to get a green solution instead of a purple one! So large magnets may not necessarily be a good
thing.
|
|
NEMO-Chemistry
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1559
Registered: 29-5-2016
Location: UK
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by MrHomeScientist ![](images/xpblue/lastpost.gif) | The older they are, the more likely they are to have SmCo magnets rather than Nd. I ran into that a few times when I got excited about some very large
magnets, then dissolved them in sulfuric acid only to get a green solution instead of a purple one! So large magnets may not necessarily be a good
thing. |
Ok so green = bad and pink = good! 2 really old ones look a nightmare to get into.
|
|
Deathunter88
National Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 514
Registered: 20-2-2015
Location: Beijing, China
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by NEMO-Chemistry ![](images/xpblue/lastpost.gif) | Quote: Originally posted by MrHomeScientist ![](images/xpblue/lastpost.gif) | The older they are, the more likely they are to have SmCo magnets rather than Nd. I ran into that a few times when I got excited about some very large
magnets, then dissolved them in sulfuric acid only to get a green solution instead of a purple one! So large magnets may not necessarily be a good
thing. |
Ok so green = bad and pink = good! 2 really old ones look a nightmare to get into. |
Huh? Every time I've dissolved magnets it has resulted in a green solution but it still produced nice pink neodymium sulphate crystals.
|
|
MrHomeScientist
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1806
Registered: 24-10-2010
Location: Flerovium
Member Is Offline
Mood: No Mood
|
|
I'd guess the green was probably iron(II) in that case, although that is also what's in the purple/pink solutions. Usually the Nd color washes out any
iron colors. Weird that it seems in some cases it doesn't. I'll admit I didn't try to process any of my green solutions, because I had plenty of
purple/pink ones to go through. Sounds like a good experiment!
[Edited on 9-12-2016 by MrHomeScientist]
|
|
Mabus
Wiki Master
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 238
Registered: 3-11-2013
Member Is Offline
Mood: Energetic
|
|
At least one of the earliest types of HDD (a big one) I took apart some time ago had a typical AlNiCo/ferrite magnet, and ferrite (?) shielding. But
they're easy to tell apart from Nd magnets: their color is black and don't react fast with acids.
|
|
Texium
Administrator
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 4547
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
That seems unlikely, being as the magnets contain far more
iron than neodymium and the color of neodymium in solution is not incredibly strong.
|
|
Sulaiman
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 3634
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Offline
|
|
From memory;
washing machine sized drives used huge ferrite magnets
scsi used SmCo
PC HDD used SmCo then Nd
small hdd used Nd and now NdPr
[Edited on 13-9-2016 by Sulaiman]
CAUTION : Hobby Chemist, not Professional or even Amateur
|
|