Sciencemadness Discussion Board

Preparing elemental fluorine in your home lab ?

metalresearcher - 25-11-2012 at 00:20

No, I am not going to do this. The intermediate product HF is already hazardous enough that I don't want to have this in my home lab.
Many chemists in the 19th century got injured, poisoned or even died while isolating F2, but that was before the fumehood and other safety equipment got invented. But even with my fumehood, safety equipment I don't do this.
Moreover no glassware can be used so custom made copper or lead tubing / vessels are required.

But are there amateurs who did this successfully in their lab ?

Random - 25-11-2012 at 03:10

I wouldn't be surprised that myfanwy made it or had it in his plans among with carbon monoxide, cyanide and phosgene. He isn't here to tell us about it though..


I think nickel could be used because it passivates, never really checked about flourine except besides curiosity..seems like something you don't wanna mess with.

[Edited on 25-11-2012 by Random]

Vargouille - 25-11-2012 at 04:23

Random is correct in that nickel is used, but steel is used as well because it too passivates with fluorine. For applications above 200C, however, nickel is required because above 200C, passivated steel will react with fluorine. It's also relatively light and inexpensive compared to the other metals that passivate with fluorine. There is a chemical route to fluorine, but it requires not only hydrofluoric acid and potassium fluoride, but also antimony pentafluoride. The electrolytic route is by electrolysis of the bifluoride ion, which requires hydrofluoric acid to produce. According to Wikipedia, the reaction temperature is between 70 and 120C, and 8-12 V are used for the electrolysis. In short, I doubt many amateur chemists have produced fluorine.

woelen - 25-11-2012 at 23:26

Quote: Originally posted by Vargouille  
[...]In short, I doubt many amateur chemists have produced fluorine.
This is a weak statement, I think that we can safely say: "In short, no amateur chemist has produced fluorine.". Even most professional laboratories do not have the equipment to handle fluorine in a safe way.

Vargouille - 26-11-2012 at 02:07

I wouldn't make the claim that no amateur chemist has produced fluorine because it is difficult and dangerous. After all, there are amateur chemists that make high explosives, phosgene, and cyanide. But it may be an unfalsifiable hypothesis, as obituaries tend not to go into detail.

plante1999 - 26-11-2012 at 02:13

Actually I'm working to make fluorine in my home lab. I almost completed the apparatus, which is made of steel and copper. The anode is carbon and the cathode is iron. I should use a 1.5 to 1 ratio of hydrofluoric acid/potassium fluoride. This mixture should only melt at 50 degree Celsius. Hydrogen is liberated in the air but at the anode a copper pipe is used to receive all anodic gases. The copper and carbon anode are isolated by sodium silicate or teflon.

I also need more fluoride to make the HF needed, I should buy some pretty soon.

I will probably use the fluorine to make cobalt trifluoride or a similar stable fluorinating agent and probably use fluorine or cobalt trifluoride to passivate nalgene HDPE container.



[Edited on 26-11-2012 by plante1999]

[Edited on 26-11-2012 by plante1999]

AndersHoveland - 26-11-2012 at 03:41

Quote: Originally posted by plante1999  
Actually I'm working to make fluorine in my home lab.

oh no, not you plante! Why couldn't it be some other member that I don't really like?


While electrolytic methods are the simplest and most direct, this information may be of interest:

MnF3 decomposes to manganese(II) fluoride above 600°C.

(2)KMnO4 + (2)KF + (10)HF + (3)H2O2 --> (2)K2MnF6 + (8)H2O + (3)O2
(solution is 50% aqueous HF, the potassium fluoromanganate precipitates out)

I am thinking that potassium hexafluoronickelate could probably likewise be prepared in a similar reaction.

At 400°C, a mixture of solid K2NiF6 and KF disproportionates/decomposes to form K3NiF6 and F2. (the reaction is reversible at 250°C).


[Edited on 26-11-2012 by AndersHoveland]

simba - 26-11-2012 at 06:32

Quote: Originally posted by Random  
I wouldn't be surprised that myfanwy made it or had it in his plans among with carbon monoxide, cyanide and phosgene. He isn't here to tell us about it though..
[Edited on 25-11-2012 by Random]


Is this the same guy who made a video on HCN production and died from phosgene poisoning?

woelen - 26-11-2012 at 07:21

Yes, it is the same guy. He did great things, but it is really sad that he had to pay this price for his endeavors :( How much risk does one want to take?

@plante1999: If you really intend to make fluorine at home, then please take into consideration the risks, not only for you, but also for the people around you (family in the house, or neighbours). If you want to do this, then you probably need to work on at least a few hundreds of grams scale and with such amounts there is a great risk of poisoning yourself or people around you.
How do you want to show that you indeed made F2? Are you collecting it in some quartz vessel so that it can be observed?

For me, the making of fluorine, or even the experimenting with concentrated HF is a big step too far. I do not feel sufficiently confident about this. This is especially true because of the insidious nature of fluorides and in particular HF. Bad warning properties, initially painless destruction of tissue, that kind of things really scares me. It is quite different from experimenting with e.g. Cl2, Br2, SO2 and so on, because these compounds have strong smells and have strong warning capabilities.

plante1999 - 26-11-2012 at 09:27

Quote: Originally posted by woelen  

@plante1999: If you really intend to make fluorine at home, then please take into consideration the risks, not only for you, but also for the people around you (family in the house, or neighbours). If you want to do this, then you probably need to work on at least a few hundreds of grams scale and with such amounts there is a great risk of poisoning yourself or people around you.
How do you want to show that you indeed made F2? Are you collecting it in some quartz vessel so that it can be observed?

I generaly do my things rather safely. I already worked with anhydrous HF, 9% 40% and I'm not dead as you can see. I'm planning to work on a 100g NaF basis. There is always risk chemistry, but when you work safely risks are minimal. Color test is not a good test, fluorine is so reactive that it should be easy to prove its presense by its reaction with iron wool. Such reaction make iron fluorides, which is much less dangerous than the fluorine.
Quote: Originally posted by AndersHoveland  

oh no, not you plante! Why couldn't it be some other member that I don't really like?




@Anders: Someone else than me may make a good explanation.

kristofvagyok - 26-11-2012 at 09:38

Quote: Originally posted by metalresearcher  
Moreover no glassware can be used so custom made copper or lead tubing / vessels are required.


Platinum or special ceramic tubing/vessels should be used, because copper also reacts with F2(:

blogfast25 - 26-11-2012 at 09:56

Plante:

”I should use a 1.5 to 1 ratio of hydrofluoric acid/potassium fluoride.”

You mean anhydrous HF?? How did you obtain or synthesise that?

Frankly, I think what you’re attempting in a home lab is FOLLY. W/o at least a decent fume hood the silliest of mishaps could be extremely dangerous. You’re not just messing with F2 but with HF too! In a sense I’m very curious to see your exploits but in another sense I just wish you wouldn’t attempt this… Also, at that ratio your fluorine is likely to be contaminated with HF due to the latter’s volatility and mechanical entrainment.

blogfast25 - 26-11-2012 at 09:57

Quote: Originally posted by kristofvagyok  
Platinum or special ceramic tubing/vessels should be used, because copper also reacts with F2(:


It passivates copper, if what I've read is correct.

kristofvagyok - 26-11-2012 at 10:18

Quote: Originally posted by blogfast25  
It passivates copper, if what I've read is correct.


At normal temperatures yes, but if it bis produced in a copper tube with electrolysis... I wouldn't be in the room.

blogfast25 - 26-11-2012 at 10:29

Quote: Originally posted by kristofvagyok  
At normal temperatures yes, but if it bis produced in a copper tube with electrolysis... I wouldn't be in the room.


Me neither, unless the quantities produced are of course really small. I think the HF is more frightening than the F2 though...

[Edited on 26-11-2012 by blogfast25]

plante1999 - 26-11-2012 at 13:50

I already made some anhydrous HF, sulphuric acid reaction with NaF in ironware and subsequent condensation. It was done during a cold day of Canada, about -30 Celsius. And yes the mixture is 1.5 Anhydrous HF, it make an HF rich potassium bifluoride. Such mixture melt at around 50 degree Celsius and passivate steel, at room temperature copper passivate effectively to fluorine, Moissant apparatus had some copper part.

After making and manipulating 30ml of Anhydrous HF I am still not dead/poisoned.

Eddygp - 26-11-2012 at 14:08

Just take enough precautions.

watson.fawkes - 26-11-2012 at 14:20

Quote: Originally posted by plante1999  
I already worked with anhydrous HF, 9% 40% and I'm not dead as you can see.
In the name of good science, please understand that this explanation, either to others or to yourself, is utterly and completely worthless. Everyone who has never had a fatal accident with fluorine can claim that they aren't dead. They make this claim in full truth and complete irrelevance.

This is an extreme example, but this class of claim is made around other dangers: "It has never happened to me, therefore it will not happen to me." Add some ass-covering nuance apparently showing fealty to probability, and you get foolhardiness.

BromicAcid - 26-11-2012 at 20:57

A few years back I was thumbing through 'Inorganic Synthesis' a compendium of laboratory techniques and preparations that is completely distinct from the other 'Inorganic Synthesis' books in our SM library. Anyway, the book contained detailed step by step details on the construction of a fluorine electrochemical cell down to power source, anode/cathode size, and even what to ask for at the hardware store. I covered a portion of the wealth of information in this post:

http://www.sciencemadness.org/talk/viewthread.php?tid=2358

So of course it could be done at home.

woelen - 27-11-2012 at 02:14

Quote: Originally posted by plante1999  
[...]I generaly do my things rather safely. I already worked with anhydrous HF, 9% 40% and I'm not dead as you can see.

The fact that you are still alive is a very good thing ;) . But also keep in mind the risk of slow poisoning. In the past, there have been people who worked a lot with HF and did not die of it, but they had adverse health effects which made them sick to some extent for the rest of their life. Also consider that. I'm not sure about names of such persons, but one of the great pioneers on fluorine chemistry also suffered from a lot of health issues after he had done a lot of experimenting with fluorides. His results were good for science, but he had to pay a high price for these results!

I second to blogfast25 that I am eager to see your results, but please think of your health. Experiments like this are fascinating, but they are not worth your health. You only have one body and there is no replacement for that!

I do not say that you should quit experimenting with HF, but I do want to warn you. I myself am quite experienced in handling highly volatile toxic and corrosive compounds (e.g. making and isolating Br2, making and isolating PBr3, making PH3) and have a decent number of chemicals and a nice collection of equipment, but for me HF (and especially anhydrous HF) is one step too far.

plante1999 - 27-11-2012 at 02:28

I admire your wisdom Woelen and I agree I have only one body. Most of the pioneers in fluorine chemistry had a poisoning from it, but I have the knowledge they acquired.

I am willing to do the experimentation's so home chemists will have reference for fluorine.

By the way I have handled and made similar volatile toxic corrosive compounds like:

150 ml of homemade bromine.
30ml anhydrous HF
H2S
40 ml of CrO2Cl2

I just don't have the wisdom/fear most of us seams to have here.

woelen - 27-11-2012 at 02:49

Fear is not good at all. If one is led by fear in his hobby, then he'd better quit that hobby.

Wisdom is another matter. I would call it respect for the materials with which you are working. I am not afraid of any chemical, but I do have utter respect for quite a few of them and HF is one of those, for which my respect goes so far that I do not want to tease it at all. Another one on my NO GO list is phosgene, COCl2.

Of the four you mentioned above I also made the other three.

Can you tell a little more about your setup, how you handle safety and what plans you have in case something really goes wrong? Maybe others can comment on that and help you with reducing the risks. With such risky endeavors it alsways is a good idea to have others think about it as well.

Mailinmypocket - 27-11-2012 at 04:25

Quote: Originally posted by plante1999  
I admire your wisdom Woelen and I agree I have only one body. Most of the pioneers in fluorine chemistry had a poisoning from it, but I have the knowledge they acquired.

I am willing to do the experimentation's so home chemists will have reference for fluorine.

By the way I have handled and made similar volatile toxic corrosive compounds like:

150 ml of homemade bromine.
30ml anhydrous HF
H2S
40 ml of CrO2Cl2

I just don't have the wisdom/fear most of us seams to have here.


Just wondering- do you have any specific plans for the fluorine you produce? How will you be storing it for later use (if at all)? I understand certain metal vessels etc can store it but that only becomes useful if the gas is somewhat pressurized so that you can dispense it as needed. I don't know if you have seen the old article I posted in the "hydrofluoric acid" thread. There are some nice experiments with HF described in those articles, which would only give you more practice with gaseous fluorides, they also are quite fun. Especially the experiment making silicon tetrafluoride, which I did yesterday and plan to continue because it is such an interesting material that doesn't wreck your glass!

Anyhow just be careful and report on your results! :)

Davin - 6-2-2013 at 01:48

KMnO4 + H2O2 +KF + HF--> K2MnF6 +H2O + O2

K2MnF6 + SbF5-> KSbF6 +MnF4

MnF4 spontaneously decomposes into MnF3 and F2

blogfast25 - 6-2-2013 at 10:11

Oh G-d, not this again :(. Trying to make small amounts of F2 at home is silly. And good luck with obtaining/preparing SbF5!

elementcollector1 - 6-2-2013 at 10:12

Quote: Originally posted by blogfast25  
Oh G-d, not this again :(. Trying to make small amounts of F2 at home is silly. And good luck with obtaining/preparing SbF5!


We can dream!