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Author: Subject: Fluorine salts aqcuisition?
testimento
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[*] posted on 1-7-2013 at 18:08
Fluorine salts aqcuisition?


Where should one start looking for fluorine salts (calcium, sodium, potassium), or even fluorite mineral? I need it to generate hydrogen fluoride for some small processes and I dont need much of it.

[Edited on 2-7-2013 by testimento]
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BromicAcid
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[*] posted on 1-7-2013 at 18:30


Fluorite is for the most part calcium fluoride and it is by far the most easily accessible and shippable fluoride. Combination of pulverized fluorite with sulfuric acid is a classic demonstration in chemistry labs. A glass plate would be covered in wax and a scene carved into the wax. Into a lead vessel pulverized fluorite would be added followed by some concentrated sulfuric acid. The glass cover would be placed over the setup and allowed to stand. The generated hydrogen fluoride would then nicely etch the glass in the exposed places. The wax would be melted off and the result given to a lucky student.

Needless to say I do not believe they do this demonstration anymore.

Regardless, this does work as a method to hydrogen fluoride. The rub however is constructing a proper apparatus to isolate the material. I am certain a search will yield more valuable information for your endeavor. Just never discount the toxicity of fluoride salts especially the volatile hydrogen fluoride.




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mayko
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[*] posted on 2-7-2013 at 08:55


If it's just HF you need, do they sell Whink rust remover where you live? It's available in my local grocery store, and is something like 5% HF.

Be careful...




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Mailinmypocket
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[*] posted on 2-7-2013 at 11:02


Calcium fluoride can be had easily on eBay etc, sodium fluoride as well...

Somewhat related, some experiments done with silicon tetrafluoride:

http://www.sciencemadness.org/talk/viewthread.php?tid=22494
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[*] posted on 2-7-2013 at 11:17


http://www.standardceramic.com/Materials.html#FF

Fluorspar, Ceramic Grade
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[*] posted on 2-7-2013 at 18:11


nice link hyfalcon :) good prices there for other stuff as well. many times I have found softball sized chunks of flourite( Ca mineral) at fleamarkets or yardsales for like 2$. worth a try if you like finding stuff for your various projects for cheap. lots of cut price cook ware that can be used for chemistry and eventually tossed/recycled/melted down/used for filler in concrete etc.
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[*] posted on 2-7-2013 at 22:31


In the old days small operations like an amateur working in their garage lab etching glass or similar endeavor, commonly kept a supply of Ammonium Bi-flouride which created Hydrofluoric Acid and Ammonia gas upon the addition of water. Obviously the NH3 had to be vented so a fume hood as well as nitrile protective gear and Calcium Gluconate gel for the HF is a good idea. Anyway back in the days of old this was the preferred method when small amounts of HF was required. Another reason was no need to store the very dangerous Hydrofluoric Acid. Much safer to store a dry powder and careful control of the water added meant no more HF than required had to be dealt with.




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woelen
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[*] posted on 2-7-2013 at 22:35


In what form do you need the HF? If you need it in the form of an aqueous solution, then I would go for NaF or NH4HF2 and acidify a solution of this. For most applications the presence of the other ions is not a real issue. NaF can be had from eBay in small quantities and is moderately soluble in water.

Starting from CaF2 is a much more dangerous process. You need to make gaseous HF first by adding sulphuric acid and passing the gas into water. In theory, the reaction is easy, but the difficult part is in the engineering of the apparatus in which the HF is generated and passed into water.




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testimento
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[*] posted on 3-7-2013 at 22:56


Great, thanks.

I dont live in USSA so the good site with ceramic matter wont help me at this time, but I saw some fluorspar and fluorite minerals for sale in my country, but the price per kg was rather astonishing, a kilogram of hydrogen fluoride would cost several hundred by that method.

An apparatus wouldn't be a problem, HF forms a passive layer on nickel alloys like 316L, which most of my ware are made of (only ditch is that they dont like chlorine which I need to use PVC and glass adapters and coatings but just about everything else, oh my - including my personal favorite, removal of solid residues of reactions with a sledgehammer), so it can be handled in common sense temperatures rather well in it.

I need the hydrogen fluoride only as synthesis gas for few reactions, so it would be generated in situ and directed to the synthesis reaction as is. It could be in water solution form too, and when Im gonna buy the fluorite salt, I will probably dismember it with acid and form a liquid solution ready for the reaction.

Unfortunately in my country, strongest wash solutions for private contain only small amounts of lye and ammonia (1-5%) and they are considered industrial in my country. I have to make everything myself, including sulfuric acid and nitrogen compounds.

[Edited on 4-7-2013 by testimento]
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[*] posted on 19-7-2013 at 19:03


Yep, got small amt NaF from FleaBay.Useful in topical aq solun. Building back up tooth enamel. The Rx toothpaste is like 1.1% NaF, and it basically looks like K-Y jelly. This, so when it dries, it adheres to your enamel. Finally you spit it out, as it is toxic. But NaF (aq) in too high a concentration, is irritating to the gum tissue. Also, I wonder weather NaF could be absorbed sublingually _ yet another potential danger.



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Antiswat
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[*] posted on 20-7-2013 at 06:52


i was working with metal some place for 2.5 years
the guy who had me so to say had this little old style candy box of metal or whatever
he had some white powder in this box, ''flux'' it was used for silver-copper welding
the point:
tasted a miniscule amount of it and i remember the taste was weird and slightly similar
found out it was NaF, sodium flouride
you could try this, you might be able to buy some if youre lucky, sold by 500g amounts if i remember correctly
otherwise on pyrogarage pl has some ''Cryolite, Na3AlF6'' this is used in pyro to enchance colours of what i know, brightness etc.
12 zl for 250g, pretty cheap, and very surely there is a way to get free F from this
you might want to try other pyro salesmen if youre not from europe, when polish has this something tells me that also american sites with their massive pyro shows and all has it




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