Sciencemadness Discussion Board

Isolating vanadium from an FeV alloy

Hilski - 15-5-2012 at 06:02

I have an FeV alloy with the following composition:

Fe ~32%
V ~55%  
Al 0.10% Maximum
Si 12.00% Maximum
C 1.00%

I'm looking for suggestions on the best way(s) to isolate the vanadium for use in other applications.
If I am able to come up with any reasonable methods, I'll post them here.
All comments - good, bad or otherwise are welcome.

Thanks

barley81 - 15-5-2012 at 07:31

I think that the first step would be to dissolve the material in acid. Sulfuric or hydrochloric could work, though nitric would be faster. Since ferrosilicon dissolves in nitric acid, this vanadium-silicon-iron alloy would probably also dissolve.

If you used nitric acid, you would probably obtain a mixture of ferric nitrate, pervanadyl nitrate, and hydrous silica. You may be able to boil down the solution with a little sulfuric acid to obtain a solid, then extract the soluble salts with water, and filter off the silica. From there, you could precipitate the iron as the hydroxide with sodium hydroxide, leaving the vanadium in solution as the vanadate ion.

I'm really not sure what happens when you dissolve a silicon-containing alloy in nitric acid. I found a book that briefly says that you can determine silicon content of ferrosilicon by dissolving in nitric acid, adding sulfuric acid and evaporating down, and then extracting the soluble salts and filtering. The book didn't say what products were formed, but silica is very likely.

The link is <a href="books.google.com/books?id=jipLAAAAMAAJ&pg=PA573&lpg=PA573&dq=ferrosilicon+nitric+acid&source=bl&ots=gYDfYQ8V4c&sig=fi2p5 QgHwFHz0U84siaTZ7xPedI&hl=en&sa=X&ei=q3OyT6HuM8af6AHV4_XNBA&ved=0CHsQ6AEwCA#v=onepage&q=ferrosilicon nitric acid&f=false">here.</a>

Hilski - 15-5-2012 at 10:10

Thanks for the reply, barley81.
I actually found another thread on SM that deals exactly with what I am trying to do.

http://www.sciencemadness.org/talk/viewthread.php?tid=13849