I'm an IT Technician and I have been interested in chemistry and E-waste recycling for a few years now. I been reading many forums and have played
around with a few safe experiments with things like copper sulfate, acetates electrolysis and a little bit of thermite. I was home schooled so I have
only basic chemistry skills and I've learnt most of my chemistry knowledge via lurking here, over at gold refining forums and some great youtube
channels like nurdrage.
Anyway, on to my question.
In my line of work I get a bit of e-waste including Lithium Ion batteries from things like laptops, tablets and phones. Unfortunately where I live,
not many places take them other than the local rubbish tip. I've been reading on disposal techniques for these which can vary from chopping them with
a, axe to drowning them with salt water. But none really address the elephant in the room.
HF
From what I have read so far, the electrolyte in Lithium Ions is Lithium Hexafluorophosphate. This, when in contact with water produces Hydrofluoric
Acid. Yeah, not something I'd particularly like to deal with. Unless this is a safe method.
I've stumbled across a patent at the same time I had an idea. Calcium hydroxide is used to neutralize the Fluorine in the electrolyte and it drops out
immediately as Calcium Fluoride.
So, here is my idea. I'd like to ask you all for your expert or amateur opinions.
Slowly discharge the Lipo with a circuit of some kind of circuit (simple or complex) to a very low voltage. Fill a large container with a saturated
solution of Calcium Hydroxide in water. Disassemble the battery and unfold the cells and separators. Individually wash the parts in the Ca(OH)2 to
neutralize the electrolyte. The HF formed in the water should bind to the Ca to form CaF2. At a guess, what is left over in the solution would be
Lithium Phosphate, Calcium Phosphate and water. The Calcium Fluoride can then be disposed of safely or used as a flux. The other compounds could also
have other uses.
I have no idea if this is correct but I'm hoping it's safer than cutting them open and dunking them in saltwater. Or my local garbage truck going up
in flames.
Fluorite - 25-1-2021 at 18:47
Oh I opened many LG & apple phone batteries before and dissolved them in hcl! Thank God I didn't get HF poisoning :3
Also keeping concentrated ammonia should convert any HF to NH4F I think fusso - 25-1-2021 at 19:09
What?! adding the battery guts in aqueous solutions produce HF?!
