Found a product online called ferrovanadium that contains the following:
V - 81,71%
Al - 0,57%
Si - 0,73%
P - 0,014%
S - 0,035%
C - 0,25%
I believe the rest is Iron. Do you guys think it would be worth trying to isolate the vanadium by use of strong acids?
Its fairly cheap but I just wanted to get some opinions/adviceOscilllator - 14-4-2015 at 02:46
It depends if this is cheaper than buying vanadium pentoxide. If it does work out to be cheaper then yes, it could potentially be worth it. But if
vanadium pentoxide is cheaper (and without seeing a link I think it is, hint hint) then it would be much easier just to buy that, since you will have
to dissolve the whole alloy in any case.bolbol - 14-4-2015 at 09:33
1kg for 60 dollars seems cheap enough. i guess the rest depends on the reagents used to purify it.
If the purity specifications are correct that is around 817 grams of Vanadium in the 1kg sample which costs around $60.
1459 grams of Vanadium pentoxide contains 817 grams of vanadium as well.
$480 is the price of 1500 grams of Vanadium pentoxide sold on ebay.
Therefor it would be profitable if it would take less than $400 dollars (the less the better obviously) to turn a kilo of into high purity vanadium
compound or metal
[Edited on 14-4-2015 by bolbol]Polverone - 14-4-2015 at 12:55
I would try using the alloy it as the anode in an aqueous solution of sodium hydroxide. The vanadium will go into solution but the iron will form fine
solids. The oxidized iron sludge is quite fine and easier to remove by prolonged settling than filtration. Or at least that has been my experience
with chromium-iron alloys.
Dissolving the whole mass in acid followed by treatment with alkali may perform the same sort of separation faster, albeit at the expense of
additional reagent consumption and hands-on labor. I wouldn't try to turn it into a profit-making endeavor. Only do it if the process interests you.
The eBay pricing you see is either for very pure material or tremendously inflated. You might pay $30 for a kilogram of pottery grade V2O5 at retail.bolbol - 14-4-2015 at 14:08
I would try using the alloy it as the anode in an aqueous solution of sodium hydroxide. The vanadium will go into solution but the iron will form fine
solids. The oxidized iron sludge is quite fine and easier to remove by prolonged settling than filtration. Or at least that has been my experience
with chromium-iron alloys.
Dissolving the whole mass in acid followed by treatment with alkali may perform the same sort of separation faster, albeit at the expense of
additional reagent consumption and hands-on labor. I wouldn't try to turn it into a profit-making endeavor. Only do it if the process interests you.
The eBay pricing you see is either for very pure material or tremendously inflated. You might pay $30 for a kilogram of pottery grade V2O5 at retail.
With electrolysis what sort of vanadium compound would be produced?
I think dissolving it in acid would be a better option for me since I understand it better than electrolysis reactions.
And its not really for business, just to get my hands on some of this stuff to mess around with in a cheaper way and a more fun way.blogfast25 - 14-4-2015 at 14:37
I think dissolving it in acid would be a better option for me since I understand it better than electrolysis reactions.
Going by reduction potentials, non-oxidising acids (HCl and H2SO4 for instance) should dissolve V to V(III). But acc. woelen, elsewhere on this forum,
dissolution of pure V in strong HCl is quite slow. The presence of iron might actually speed things up a bit.
If I was in your place (and in the absence of better information) I would try and dissolve it in an excess of 50 w% H2SO4 at BP (with reflux) and see
what happens.
After filtering, oxidise both the Fe and V with hydrogen peroxide (or even bleach). Fe becomes Fe<sup>3+</sup>, V becomes
VO<sup>3+</sup>. Then strongly alkalise with NaOH which precipitates Fe as Fe(OH)<sub>3</sub> and solubilises V as meta or
orthovanadate.
[Edited on 14-4-2015 by blogfast25]bolbol - 14-4-2015 at 16:01
That doesnt sound bad.
I was thinking of using nitric acid originally. There is no mention of vanadium being oxidized by nitric acid. I thought id filter of everything then
and use dilute HCl to get any iron oxide products from the iron nitrate decom soluble again and be leftover with vanadium metal.
But the uncertainty is an issue. Either way I could try with a small sample. blogfast25 - 14-4-2015 at 16:59
Vanadium steels and bronzes, and ferrovanadium, are decomposed by the methods used for other steels; the drillings are, for instance, dissolved in
sulphuric acid [...]
Nitric acid can oxidise V to V(IV), going by reduction potentials but that doesn't mean it will actually happen.
Trying both is probably your best bet unless someone can unearth more tried and tested information.
It states that the metal gets oxidized to vanadic acid in cold or hot nitric acid. Which according to wikipedia falls out of solution as V2O5 due to
instability.
It also has tons of other information that I will look into.blogfast25 - 14-4-2015 at 18:36
Whatever you do, it'll never be very quick though, because that product is bulk, not powder and that's a big drawback.bolbol - 14-4-2015 at 18:43
Yes indeed. Unless i find a way to hammer it down if its brittle enough and not splash it all over the placeblogfast25 - 15-4-2015 at 15:50
Quite a bit more information on extracting vanadium from ferrovanadium here:
[Edited on 15-4-2015 by blogfast25]Oscilllator - 15-4-2015 at 16:01
I would be *very* wary of going the route where you oxidise a large amount of material with hydrogen peroxide. Unless you have access to cheap,
plentiful 30% H2O2 I think you would be better off going another route, because if you use 3/6% H2O2 you will spend a lot of money to end up with vast
quantities of a dilute solution.
Polverones idea sounds ideal to me, unless the iron doesn't flake off properly and you get passivation of the anode.blogfast25 - 15-4-2015 at 16:45
Oscillator:
Personally I haven't much experience with electrolytic dissolution/oxidation of metals, so I wouldn't go there.
Point taken on the peroxide. But I've used 30 % H2O2 many times for the oxidation of Fe(II)/Fe(III) and you don't really need that much.
But I'm already thinking of a different route.
Dissolve alloy in 50 w% H2SO4 with reflux. Dilute and filter.
Add equivalent of NaOH to obtain neutrality and mixed Fe(II) / V(II/III?) hydroxides precipitate. Filter off and wash filter cake a bit.
Then air (oxygen) oxidise filter cake to Fe2O3 and V2O5 on modest heat, stirring and turning regularly. Add small amounts of water to
keep things moistish.
Leach oxidised precipitate with NaOH solution to extract vanadate, leaving ferric oxide behind. It's not fully clear to me whether oxygen can oxidise
V(II,III?) to V(V) but it will certainly oxidise it to V(IV), which could (?) then be leached out as hypovanadate,
V<sub>4</sub>O<sub>9</sub><sup>2-</sup>, at high pH.
