Sciencemadness Discussion Board

What to do with a bottle of 60% HF?

Keras - 21-5-2019 at 01:16

So, there it is. I’ve ordered a bottle of 60% HF, because it was not that expensive, but I have no idea what to do with it except spill it on limestome gravel to make CaF2.

Any suggestion? Fluorosulfonic acid? Mixing it with nitric acid doesn't seem to lead to new products, just a powerful etchant. Can I get trifluoroacetic acid from HF and glacial acetic acid?


[Edited on 21-5-2019 by Keras]

Pumukli - 21-5-2019 at 01:55

This is not a toy, but of course you are well aware of it. :-) Don't spill it on anything living, if possible!

If you want to "waste" it on CaCO3 then do it, though avoid the escaping fine mist...

If I were you I'd convert it into something less toxic but still usable thing, say NaBF4. Dissolve it in borax-NaOH mixture, or something like that, look up the relevant preparation in an inorganic lab manual.

WGTR - 21-5-2019 at 01:56

Are you aware of the special hazards that this material possesses? Burns are not immediately obvious, and bind up the calcium in your body, the kind that bones need for support, and nerves need to function. It’s a painful death. When I have used it I use two pairs of long gloves, have a neutralizing solution and running water nearby, and have fresh tubes of calcium gluconate gel as an antidote. That’s just what gets applied to skin while on the way to the hospital.

To answer your question, I’ve used it to etch glass slides to make micro channel reactors. That was cool.

woelen - 21-5-2019 at 02:04

Why do you order chemicals when you do not know what to do with it? Especially HF is really nasty. The 60% acid also is strongly fuming and for that reason it is VERY hard to handle safely.

If I were you, I would dilute it to 40% or so, making it a non-fuming liquid, which is much easier and safer to handle. But still, with 40% acid you have to be very careful. Getting it on your body will cause really serious health issues or even death.

One interesting thing might be to convert the acid to HBF4, using B2O3. Beware with the reaction, it is quite exothermic, slowly add B2O3 to the acid in small portions. Try to use as precisely as possible the right stoichiometric amount of B2O3 and after the final addition, add 1% more of B2O3 to assure that no free HF is present anymore. This slight excess of B2O3 will cause formation of a little mixed fluoro/hydroxo boric acids.

Keras - 21-5-2019 at 02:08

Quote: Originally posted by WGTR  
Are you aware of the special hazards that this material possesses? Burns are not immediately obvious, and bind up the calcium in your body, the kind that bones need for support, and nerves need to function. It’s a painful death. When I have used it I use two pairs of long gloves, have a neutralizing solution and running water nearby, and have fresh tubes of calcium gluconate gel as an antidote. That’s just what gets applied to skin while on the way to the hospital.


Don't worry. I'm not a daredevil. I know pretty well where I'm going and have read extensive litterature on how to handle HF safely. Besides, I don't intend to use more than a very few milliliters at once. And yeah, I have calcium gluconate available, and I'll dip the HF bottle in a cold water + CaCl2 bath to take care of dripping.

karlos³ - 21-5-2019 at 02:14

I had a colleague who got some on his finger, tiniest little drop without noticing, then after work, it started to became a noticeable pain.
The next day they amputated his finger tip(luckily he only got it on the tip).
Be really careful with it!

Keras - 21-5-2019 at 02:14

Quote: Originally posted by woelen  
Why do you order chemicals when you do not know what to do with it? Especially HF is really nasty. The 60% acid also is strongly fuming and for that reason it is VERY hard to handle safely.


I agree. That sounds dumb. I did it because I’m not sure I'll be able to get it later if I need it for whatever purpose. I don't like stockpiling, but in this case, given the way less and less reactants are available, I finally gave in. I pondered much before, though, as I'm perfectly aware of the risks this product poses.
Quote: Originally posted by woelen  

If I were you, I would dilute it to 40% or so, making it a non-fuming liquid, which is much easier and safer to handle. But still, with 40% acid you have to be very careful. Getting it on your body will cause really serious health issues or even death.

One interesting thing might be to convert the acid to HBF4, using B2O3. Beware with the reaction, it is quite exothermic, slowly add B2O3 to the acid in small portions. Try to use as precisely as possible the right stoichiometric amount of B2O3 and after the final addition, add 1% more of B2O3 to assure that no free HF is present anymore. This slight excess of B2O3 will cause formation of a little mixed fluoro/hydroxo boric acids.


I don't have B2O3, but I have boric acid and a heating mantle that goes to 400 °C, so I suppose I could make it by dehydrating boric acid. Ever done that? EDIT: Apparently, HBF4 can be directly synthesised using boric acid, so the dehydration is not necessary.
Quote: Originally posted by karlos³  
I had a colleague who got some on his finger, tiniest little drop without noticing, then after work, it started to became a noticeable pain.
The next day they amputated his finger tip(luckily he only got it on the tip).
Be really careful with it!


I have ordered full size, thick nitrile gloves, and I'll wear standard blue thin nitrile gloves underneath.

[Edited on 21-5-2019 by Keras]

draculic acid69 - 21-5-2019 at 04:25

Dissolve a dead body.exactly how much HF does it take to dissolve someone. For example take 1kg of chicken carcass bones, blood,skin,meat etc and see how many ml's of fuming HF acid it takes to make it into something that can be poured down the drain.before anyone winges and moans this is a perfectly valid experiment.

Keras - 21-5-2019 at 05:25

Quote: Originally posted by draculic acid69  
Dissolve a dead body.exactly how much HF does it take to dissolve someone. For example take 1kg of chicken carcass bones, blood,skin,meat etc and see how many ml's of fuming HF acid it takes to make it into something that can be poured down the drain.before anyone winges and moans this is a perfectly valid experiment.


This has already been done and with HCl and sulphuric acid as comparison.

draculic acid69 - 23-5-2019 at 02:20

I'll be sure to check that out.thanks