Tacho - 7-11-2004 at 04:03
As a byproduct of my electrolytic steel etching I got a black powder that is very ferromagnetic. Since iron produces many oxides and complex ions, I would like to know
if there is more than one that is black, insoluble and strongly ferromagnetic?
Saerynide - 7-11-2004 at 06:47
Fe3O4?
Organikum - 7-11-2004 at 07:09
On http://www.kremer-pigmente.de you find very good information on the several oxides of iron, properties uses and more.
To me it sounds you got this black iron oxide which is used as pigment for cement and concrete.
Its on the page linked above.
vulture - 7-11-2004 at 13:11
Is it stainless steel or somekind of alloy? Because it could also be NiO then.
Tacho - 7-11-2004 at 13:33
No, it's just a common nail. Rather big though. So far, the best bet is magnetite (Fe3O4) mixed with other oxides, as Saerynide pointed out.
I'm gravity filtering it to do further tests. I read somewhere that there is a FeO that oxidizes when exposed to air.
A magnetic non-conductive fine powder that does not rust is interesting material...
This is a thread that I found in the usenet. A guy did what I did, exactly with a nail, and someone told him "With the exception of aluminum
and magnesium, no other metal oxide can be formed by electrolytic action".
Curious... someone is very wrong...
mick - 9-11-2004 at 10:42
I think Fe3O4 is the least soluble of iron oxides in dilute acid and readily magnetised with heat or a magnet. If you powder the oxide, put it in a
tube, pass a magnet over it and then hold a non magnetised nail next to the tube you should separate the Fe3O4. With it magnetised you could give it a
quick wash with dilute sulfuric, maybe borax, and water, then dry it well. I think it is fairly stable in air if dry. Water seems to convert it to
Fe2O3
mick
rocketscience - 25-11-2004 at 08:35
I have the same question however you could have iron hydroxide because from what I remember mine had a green tint to my electrolysis it butt it was
mainly black but then when it all settled it was a dark grayish blue did you see any similar colors
ATTENTION ROCKETSCIENCE
Polverone - 25-11-2004 at 13:30
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