[thaqrhys]

Dear everyone,

I've ever throw a topic about purifying HF. Actually the main goal is getting Fluorine (F2).

I was thinking to react Cl2 + 2HF -> F2 + 2HCl

But, the HF must be anhydrous while I only have HF 55%.

Now, I'm considering to react :

( 1 )    CaF2 + H2SO4 -> 2HF + CaSO4

( 2 )    BaF2 + H2SO4 -> 2HF + BaSO4

which is more economic ?

Or any other ways in order to get F2 ?

Thanks before.

[lemonoman]

Dear taqrhys

What do you need the fluorine for?  Can you use anything else like sulfur hexafluoride or boron tetrafluoride or something?

The experiment you propose is probably the most dangerous thing I've ever seen, second only to that guy who suggested making paintballs with glass...There are millions of safer ways to get F2.

One of which, is buying it.  Different companies will offer gases depending on your country.

Asia, Europe, North and South America can go to Praxair....you might have to call them and talk about ordering a "Specialty Gas" (Link)

[thaqrhys]

thanks for your suggestions,lemonoman..

if it's too dangerous to be done, what other ways of reaction which is much safer?

i want to make sulfuryl fluoride, that's why i want to synthesize fluorine by myself.

i could just buy it, but after this lab scale, i want to go to commercial one, and i think it would be more economical if i produce it on my own.

thanks anyway for your concern.

[lost and found]

I was thinking to react Cl2 + 2HF -> F2 + 2HCl

This doesn't work. Fluorine is a much stronger oxidiser than chlorine. It will work in the opposite direction, though.

Here's three reactions that might help:
SO2 + KF --> KSO2F
KSO2F + Cl2 --> SO2ClF + KCl
SO2ClF + KSO2F --> SO2F2 + KCl + SO2 (@180 celsius)

SO2 and SO2F2 are both gases. However, SO2 condenses at about -10 celsius, while SO2F2 condenses around -55 celsius

[thaqrhys]

Thanks for your suggestion..

I got the reaction Cl2 + 2HF -> F2 + 2HCl from US Patent, so I was quite confident with it.
But, after knowing your advice, i would rethink again of it.

I appreciate your alternative given.

Does it require any catalyst ?

And water ? Because the side product KCl will be solid.

[AWK]

I think the best method of F2 production is an electrolysis of molten KF, but it should be done i well equipped labs.

[lost and found]

I think the best method of F2 production is an electrolysis of molten KF, but it should be done i well equipped labs.

I think it would be better to use KF dissolved in liquid HF. You don't have to heat it to melt anything. Also, the KF isn't consumed because it's easier to seperate H and F. (P. S. this is the commercial method of preparing F2 gas)

[AWK]

I think it would be better to use KF dissolved in liquid HF. You don't have to heat it to melt anything. Also, the KF isn't consumed because it's easier to seperate H and F. (P. S. this is the commercial method of preparing F2 gas)

I doubt - mixture of H2 and F2 is very explosive

[puppy8800]

you'd better purchase fluorine than synthesize it
synthesizing F₂ hadn't been successfully done until 1986
and it was quite a complicated method, using SbF₅, a stronger Lewis acid, to exchange a weaker and unstable Lewis acid MnF₄
the electrolysis of the mixture of KHF₂ and HF is used to produce fluorine in industry, and fluorine and hydrogen must be strictly seperated
the decomposition of BrF₅ or K₂PbF₆ can be used to produce fluorine in labs

[lost and found]

I doubt - mixture of H2 and F2 is very explosive

Good point, I thought I would just mention that method. I didn't say it was practical at home!

[thaqrhys]

well, according to all of you, that synthesizing F2 in lab is practically dangerous. For a moment, I'll get the Fluorine aside and start working on the reaction involves KF instead of HF.

I just could purchase the fluorine gas for now, but anyway, in the future ( on the scale up ) I've to rethink of producing the fluorine.

Decomposition of fluoride compounds ( SbF5 ) is more interesting and safer likely.

 

[thaqrhys]

I was thinking to react Cl2 + 2HF -> F2 + 2HCl

This doesn't work. Fluorine is a much stronger oxidiser than chlorine. It will work in the opposite direction, though.

Here's three reactions that might help:
SO2 + KF --> KSO2F
KSO2F + Cl2 --> SO2ClF + KCl
SO2ClF + KSO2F --> SO2F2 + KCl + SO2 (@180 celsius)

SO2 and SO2F2 are both gases. However, SO2 condenses at about -10 celsius, while SO2F2 condenses around -55 celsius

Hi guys,

I bring this topic to the surface again, i wanna give improvement based on your thoughts and helps.

So, i tried the reactions above ( thanks "lost and found" ! ). I synthesize chlorine from Ca(OCl)2 + HCl ( also from this forum ) and SO2 from sodium sulfite+HCl. But, since I didn't have KF, I substituted it with BaF2.

I did the reactions, and I got colorless gas which I put in ampoule. I haven't tried to check it by condensing it. I tested the gas to cockroach. I injected 2 mL to the jar filled with a cockroach, and it's dead. So, until now, I concluded that the gas is very poisonous, and I believe the gas contains SO2F2 ( the gas I tried to make ) in small amount.

That's the improvement until the day before X'mas.

After X'mas and New Year break, I'll try to :
1. Test the gas composition with GC.
2. Conduct the same reaction with longer reaction time and more precise amount of the reactant in order to get higher purity of SO2F2.
3. Conduct the reaction with KF ( I'm waiting for the KF I ordered. )

That's the follow up of our discussions, guys. Thanks anyway and I'll be waiting for critics and suggestions.

[heidi]

is it possible to make f2 from caf2? at least theoretically...