greenyppols - 24-4-2007 at 15:19
Seems wierd, but I did search on how to clean iron filings, if its even practically possible.
I acquired some iron filings and decided to play around a bit with a magnet and white paper. It left a brown stain I can assume is rust.
The package is a cardboard cylinder, not what I'd call air-tight, especially since Iron rusts...doh
I checked how to clean iron in the Purification of Lab Chemicals (it has an inorganic section) and for Iron WIRE it says to clean in concentrated hcl,
then acetone and dry under vacuum.
Now thats for wire, but wouldnt iron filings just...well...dissolve away?? Anyone clean iron filings before? Is this practical? I searched google and
this site also. Ideas, anyone?
Thanks
not_important - 24-4-2007 at 15:49
The exposure to HCl is meant to be short, enough to dissolve the surface oxidation; the acetone wash and vac dry is to prevent the iron from
reoxidising.
What to do to clean is going to depend of the origin of the filings and what you intend to do with them.
greenyppols - 25-4-2007 at 01:11
Thanks n_i
yeah, I figured what the acetone and vac was for, but its the "short" part of washing with hcl that has me wondering if it was even worth the bother
before I tried. Being filings, there isnt much to begin with...and not much to see.
I may just buy some filings I know will be off better quality, I've never heard of "reagent grade" iron filings, but then I havent looked yet.
not_important - 25-4-2007 at 04:34
Reagent grade in this case means pure iron, instead of some alloy that could contribute metals you don't want; what those might be depends on the use
of the filings. Plus there's be no oil or other organics mixed in.
If you electroplate iron from solution with a fairly high current density, you get a poorly adhering layer of somewhat brittle iron. This crushes and
ball mills down to a powder fairly easily. I'm not suggesting you do this, it's going to take 40 amp-hours or more to get a mole of iron (real world,
current inefficiency), but if you want reagent iron powder that's one way to get it.
On the other hand, many reductions are happy with iron or steel filings and chips, just so long as they were well washed to remove cutting fluids.
chemrox - 25-4-2007 at 21:00
if you need to store the cleaned filings you can place them in a vacuum dessicator overnight and store them in a bottle flushed with inert gas. if
you can't get N2 from a welding supply you can buy a small tank of helium at costco