theAngryLittleBunny
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making V2O5 from ferrovanadium
Hello there,
So I just wanted some V2O5 for some experiments, but V2O5 is really expensive here. The cheapest source of vanadium I found was a ferrovanadium alloy
with 81% vanadium, 18% iron and 1% other stuff. So I though I just make V2O5 from that. Basically, I planned on oxidizing the vanadium to V(5+), and
then make the solution alkaline to precipitate the iron as iron hydroxide while the vanadium stays in solution as vanadate. Then I could just filter
it and neutralize the solution to precipitate V2O5. Sounds easy, but the differcult thing is just to dissolve the vanadium. I could just use nitric
acid to make vanadyl nitrate VO(NO3)2, but it takes about 4 parts of nitric acid to dissolve 1 part of ferrovanadium. I also thought about a 1:1 molar
mix of sulfuric acid and nitric acid, which would dissolve it to vanadyl sulfat VOSO4, but you would still need a lot of nitric and sulfuric acid, and
the volume of the solution would get quite big, which I don't want. So my question is, does anyone know a really easy way to basically turn vanadium
metal into V2O5 that I might not have thought about?
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unionised
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I haven't tried it, but I wonder if an alkaline solution of hydrogen peroxide would dissolve it as vanadate (and/ or peroxy-vanadates) while leaving
the iron behind as an oxide.
Powdering the alloy and oxidising it by heating in air, followed by alkaline extraction might also work.
Air is cheap.
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Aqua-regia
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Ive experience what you want with. Dissolve the ferrovanadium in 30-35% nitric acid. The ferrovanadium dissolving by heating easy. Evaporate the
solultion to dryness, and heat the solid above 300 degrees, to get vanadiumpentaoxide. (Lot of NO x fumes!)
Purification: via ammoniumvanadate. Literature Brauer: Handbook of Preparative Inorganic Chemistry 1963, page 1272 .
If your ammoniumvanadate not enough pure (will not) get the vanadiumpentaoxide by heating of ammoniumvanadate, and the purification process repeat
again. Simple and very effective route . Good luck fellow.
[Edited on 21-1-2018 by Aqua-regia]
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theAngryLittleBunny
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Quote: Originally posted by unionised  | I haven't tried it, but I wonder if an alkaline solution of hydrogen peroxide would dissolve it as vanadate (and/ or peroxy-vanadates) while leaving
the iron behind as an oxide.
Powdering the alloy and oxidising it by heating in air, followed by alkaline extraction might also work.
Air is cheap. |
The alkaline H2O2 idea sounds interesting, I thought about a more extreme approach of dissolving it in a molten mix of NaOH and NaNO3. And NO, I can't
powder this stuff, no waayyy.
| Quote: Originally posted by Aqua-regia | Ive experience what you want with. Dissolve the ferrovanadium in 30-35% nitric acid. The ferrovanadium dissolving by heating easy. Evaporate the
solultion to dryness, and heat the solid above 300 degrees, to get vanadiumpentaoxide. (Lot of NO x fumes!)
Purification: via ammoniumvanadate. Literature Brauer: Handbook of Preparative Inorganic Chemistry 1963, page 1272 .
If your ammoniumvanadate not enough pure (will not) get the vanadiumpentaoxide by heating of ammoniumvanadate, and the purification process repeat
again. Simple and very effective route . Good luck fellow.
[Edited on 21-1-2018 by Aqua-regia] |
That sounds like an easy preperation, the problem is that it takes a LOT of nitric acid, if I'am optimistic, I would say the reaction is something
like this:
6HNO3 + 2V -> 2VO(NO3)2 + N2O + 3H2O
So you need almost 4 parts of pure nitric acid for one part of vanadium, which means 12 parts of 33% HNO3, so I don't really like that methode, but
thanks for your help.
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clearly_not_atara
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The hydroxide/nitrate fusion method works:
https://www.inorganicventures.com/samples-containing-vanadiu...
I don't think vanadyl nitrate is the primary product of dissolving vanadium in nitric acid, though; that seems a bit off. I would expect V2O5 to be
produced unless concentrated nitric acid is used.
I imagine you could use bromine monochloride:hydrochloric acid, BrCl*HCl, which is formed when Br+ is dissolved in excess hydrochloric acid. In one
case, elemental bromine was added to hypochlorite:
http://repository.ias.ac.in/42094/1/42094_pub.pdf?origin%3Dp...
in another case, bromate and bromide are added together to HCl:
http://www.sciencedirect.com/science/article/pii/00399140588...
I suspect one could use a 1:1 molar ratio of bromide salts to hypochlorite to obtain the requisite "hypobromite" (an unstable anion) solution,
although this simpler version is absent from the literature. An excess of bromide is preferable to prevent chlorine evolution. The concentration of
BrCl should not be higher than 0.2M.
[Edited on 21-1-2018 by clearly_not_atara]
[Edited on 04-20-1969 by clearly_not_atara]
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theAngryLittleBunny
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I just tried the NaNO3 NaOH fusion methode, and it works amazing! I never knew that a solid and quite unreactive piece of metal could react like that
O.o The only drawback is that you have to use quite a lot of excess NaOH or NaNO3 as a "solven", or else everything becomes solid before it has fully
reacted, but I think that's the methode I'll use. I really don't wanna waste any bromine, bromate or even bromide on this methode tho, because that
seems a bit unnessecary.
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j_sum1
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Following with interest. I have begun a project to extract V from screwdriver bits. (There is only about 0.5% in there so it is mostly for
interest.)
I have begun by putting the bits in HCl to dissolve them -- a process that I think will take weeks if not months. But I do have some more tool steel
around and so might try this method -- keeping in mind that 0.5% is not 80% and tool steel is not ferrovanadium.
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theAngryLittleBunny
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| Quote: Originally posted by j_sum1 | Following with interest. I have begun a project to extract V from screwdriver bits. (There is only about 0.5% in there so it is mostly for
interest.)
I have begun by putting the bits in HCl to dissolve them -- a process that I think will take weeks if not months. But I do have some more tool steel
around and so might try this method -- keeping in mind that 0.5% is not 80% and tool steel is not ferrovanadium. |
I don't think the NaNO3 NaOH fusion methode works for iron, because the metal oxide needs to make a salt, like Na3VO4, Fe2O3 can't do that. But mabye
I'am wrong, the huge disatventage of this methode is that you need a ton of acid to neutralize the Na3VO4. I have about 550g if the ferrovanadium, and
I would need about 2 to 3 liters of acetic acud to neutralise the Na3VO4 from that.
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clearly_not_atara
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I think you could neutralize most of it by bubbling CO2 if you want to save money... just light some organics on fire and vent the outgas pretty much
[Edited on 04-20-1969 by clearly_not_atara]
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Aqua-regia
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Some remark for you Little Bunny:
Google in your area metallurgical trader and request 50-100 g sample of ferrovanadium- It is free for charge ,surely. This is nothing for those
companies. I've done it. Also manganese and chromium. Forget vanadium hardened tools .
The stochiometric balance:
6 V + 10 HNO3 ——> 3 V2O5 + 10 NO + 5 H2O↔
V2O5 + 2 HNO3 ↔ 2 (VO2)NO3 + H2O
Nitric acid is cheaper than NaOH +H2O together. One liter technical grade max 1-2 USD/ lit.
The pulverising of ferrovanadium is a big sucks, quite hard stuff. That reason the moltening process giving poor yield. The HNO3 each it in big
lump very quick too. I dissolved walnut measure lumps without grinding. I am over with NaOH + H2O2 methode. The dissolving velocity is too slow,
needing a lot of reagent.
OK, the evaporation and decomposition of nitrate needing fume hood or big backyard. Dont using in excess HNO3, better a small residue of
ferrovanadium.
[Edited on 22-1-2018 by Aqua-regia]
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theAngryLittleBunny
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| Quote: Originally posted by clearly_not_atara | | I think you could neutralize most of it by bubbling CO2 if you want to save money... just light some organics on fire and vent the outgas pretty much
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This would only bring it to the meta vanadate tho, you need a stronger acid to precipitate V2O5. I thought about acetic acid, but even that is too
weak. I think I'am just gonna use sulfuric acid, I'am just gonne need a liter of it .-.
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theAngryLittleBunny
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| Quote: Originally posted by Aqua-regia |
Some remark for you Little Bunny:
Google in your area metallurgical trader and request 50-100 g sample of ferrovanadium- It is free for charge ,surely. This is nothing for those
companies. I've done it. Also manganese and chromium. Forget vanadium hardened tools .
The stochiometric balance:
6 V + 10 HNO3 ——> 3 V2O5 + 10 NO + 5 H2O↔
V2O5 + 2 HNO3 ↔ 2 (VO2)NO3 + H2O
Nitric acid is cheaper than NaOH +H2O together. One liter technical grade max 1-2 USD/ lit.
The pulverising of ferrovanadium is a big sucks, quite hard stuff. That reason the moltening process giving poor yield. The HNO3 each it in big
lump very quick too. I dissolved walnut measure lumps without grinding. I am over with NaOH + H2O2 methode. The dissolving velocity is too slow,
needing a lot of reagent.
OK, the evaporation and decomposition of nitrate needing fume hood or big backyard. Dont using in excess HNO3, better a small residue of
ferrovanadium.
[Edited on 22-1-2018 by Aqua-regia] |
1 to 2 dollars per liter? Now you're making me jealous .-. Here in europe, HNO3 over 3% is restricted, because of explosives and stuff. I literally
have to distill it from nitrate fertilizer, amd that's really tedious and boring. And HNO3 can't oxidize vanadium past the +4 oxidation state, at
least from my experience. I tried that, and I just get a deep blue solution, which is the VO(2+) ion. But if the reaction equasions you wrote there
are really true, it would actually be viable to use HNO3 still.
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Aqua-regia
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Ok but i wrote technical grade with 50-55% . This is cheap in IBC container or 20 lit. PE bottle. If you have some contact with horticulture farmer
with greenhouse, you can get it. Using it to dropping irrigation very diluted form.
Iam living in south-east europe it is no problem to buying. (this is a part of free world in Europe compare with Germany or France)
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theAngryLittleBunny
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| Quote: Originally posted by Aqua-regia | Ok but i wrote technical grade with 50-55% . This is cheap in IBC container or 20 lit. PE bottle. If you have some contact with horticulture farmer
with greenhouse, you can get it. Using it to dropping irrigation very diluted form.
Iam living in south-east europe it is no problem to buying. (this is a part of free world in Europe compare with Germany or France)
|
Oh, I live in Austria, there things which are toxic or were used in explosives are restricted. But the more important question is, can HNO3 oxidize
Vanadium in the +5 oxidation state? I mean maybe you tried it, and it did that.
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Aqua-regia
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Sure, piece of cake:
this picture: dissolving the ferrovanadium
Attachment: php9wjcu7 (73kB)
This file has been downloaded 621 times
[Edited on 23-1-2018 by Aqua-regia]
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Aqua-regia
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next one:
the decomposed nitrate (crude V2O5) with iron impurity
[Edited on 23-1-2018 by Aqua-regia]
Attachment: phpSpeHnc (102kB)
This file has been downloaded 662 times
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clearly_not_atara
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Vanadyl nitrate is VO(NO3)3, not VO2NO3, and it's yellow, not blue. The blue color might be explained by the presence of VO(NO3)2 which could still
decompose to V2O5 via a reaction like 4VO(NO3)2 >> 2O2 + 2V2O5 + 7NO2. Unfortunately both VO3+ and VO2+ have been referred
to as "vanadyl"...
[Edited on 04-20-1969 by clearly_not_atara]
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theAngryLittleBunny
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| Quote: Originally posted by clearly_not_atara | | Vanadyl nitrate is VO(NO3)3, not VO2NO3, and it's yellow, not blue. The blue color might be explained by the presence of VO(NO3)2 which could still
decompose to V2O5 via a reaction like 4VO(NO3)2 >> 2O2 + 2V2O5 + 7NO2. Unfortunately both VO3+ and VO2+ have been referred
to as "vanadyl"... |
VO(NO3)3 hydrolyses in water, so I don't think it would be in the solution. I mean I could try to use an obvious excess of HNO3 to see if it turns
yellow.
Thank you! Just one more thing, what is the ration of HNO3 and Vanadium metal you use?
[Edited on 23-1-2018 by theAngryLittleBunny]
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Aqua-regia
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I used ferrovanadium lump, cca 10 g, and in small portion added 30% HNO3, till almost the whole metal dissolved. It was not able to making
precalculation, because i had no glue before, what is the Fe /V ratio. I gained cca. 55% result of vanadium from this one.
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fusso
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| Quote: Originally posted by theAngryLittleBunny | Hello there,
So I just wanted some V2O5 for some experiments, but V2O5 is really expensive here. The cheapest source of vanadium I found was a ferrovanadium alloy
with 81% vanadium, 18% iron and 1% other stuff. So I though I just make V2O5 from that. Basically, I planned on oxidizing the vanadium to V(5+), and
then make the solution alkaline to precipitate the iron as iron hydroxide while the vanadium stays in solution as vanadate. Then I could just filter
it and neutralize the solution to precipitate V2O5. Sounds easy, but the differcult thing is just to dissolve the vanadium. I could just use nitric
acid to make vanadyl nitrate VO(NO3)2, but it takes about 4 parts of nitric acid to dissolve 1 part of ferrovanadium. I also thought about a 1:1 molar
mix of sulfuric acid and nitric acid, which would dissolve it to vanadyl sulfat VOSO4, but you would still need a lot of nitric and sulfuric acid, and
the volume of the solution would get quite big, which I don't want. So my question is, does anyone know a really easy way to basically turn vanadium
metal into V2O5 that I might not have thought about? |
What metal objects are made of that FeV composition?
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