Sciencemadness Discussion Board

Iron - reduced

Organikum - 22-9-2004 at 14:47

I am looking for a way to produce reduced iron in reasonable purity and amounts which should somehow resemble the state of "reduced iron".
I want to avoid jokes like "reduce iron powder under a flow of hydrogen at a temperature of 600°C..." though.
I know that electrolysis might produce iron of the wanted purity, but how to reduce this in a easy way? I guess anything including water wont work, but I am by no way sure.


Any ideas welcome.
Practical ideas even more welcome.
:D

A simple way starting from black iron oxide would be the hit, for I can buy this as ultrafine powder for cheap. (pigment for cement/concrete)

[Edited on 22-9-2004 by Organikum]

Mephisto - 22-9-2004 at 15:29

This is interesting, but just another joke, as it is to difficult to synthesize the iron pentacarbonyl:

Fe(CO)<sub>5</sub> <u>&nbsp; 150–250° &nbsp;</u><sub>&gt;</sub> Fe + 5 CO

The electrolysis (the only possible way at home) should be done with a car battery charger, because it gives enough amperes without overheat. Make it like the example in "Brauer" (page 1640) 800 g FeCl2 x 4 H20 in one litre water at 90 °C. Graphite or Fe as anode and stainless steel as cathode. Plus some HCl.

Fe (pyrophoric) via Oxalate decomposition

chemoleo - 22-9-2004 at 15:42

The title says it. Make yellow iron oxalate (II) via dissolution of FeCl2 with Na2C2O4, the iron oxalate precipitates. This has to be dried thoroughly.

In a testtube, with some glass wool at the top, this is heated under the Bunsen until the colour goes black.
After cooling, when shook out to the air, it self-ignites.

However, the problem is residual oxygen - so part of the Fe will Fe3O4. This problem is proabably mostly avoided by decomposing a LARGE amount of FeC2O4, whereby O2 is flushed out together with nascent CO2.
It's a nice experiemnt by the way :)

PS of course you can make iron via the thermite route too.

Quote:

reduce iron powder under a flow of hydrogen at a temperature of 600°C...

I dont understand, how are you going to reduce it any further if it is iron already? Surely you mean iron oxide?

Mephisto - 22-9-2004 at 16:14

The pyrophoric iron is a really nice experiment. The mix in the test-tube is Fe and FeO (according to "Chemische Kabinetstücke";). So you can try to separate the FeO from the Fe by adding a weak acid under inert gas. But I don't think it's worth the trouble.

chemoleo - 22-9-2004 at 16:42

So do you therefore make a mix of CO and CO2?
Oops I didn't know that - I always assumed full decomposition would be favoured - because I thought, either you'd get FeO only (and CO), or Fe only (and CO2). Didnt think this would be a mixture... damn equilibrium again!

Organikum - 23-9-2004 at 00:49

Thanks!
Chemoleo, many organic prparations call for "prereduced" iron powder or tell that "hydrogen reduced iron powder" was used, I guess usually iron powder consists of iron with a certain amount of ironoxide as impurity.

Mephisto, seems I overloooked this in the Brauer´s, uups.

Btw. would it be possible to use acetic acid/water as electrolyte and FE(II)acetate as salt? Avoiding chlorine contamination?

Mephisto - 23-9-2004 at 01:26

I think it's possible to use Fe(II)acetate/acetic acid as electrolyte, but I don't know for sure. As acetic acid didn't dissociate such as HCl, the conductivity will be lower and you need more 'power' for your electrolysis. On the anode you'll get CO2 and ethane (Kolbe dimerization) and some methanol (non-Kolbe reaction) in the liquid phase.

Dodoman - 23-9-2004 at 07:13

Correct me if I'm wrong but won't you get Fe from a thermite reaction....?
I think it'll be pure if you designed a container to separate the slag from the mixture by simply leting it settel down. They should form two layers which won't be hard to separate.

Mephisto - 23-9-2004 at 07:56

Via thermite reaction you'll get one piece of iron and not the desired powder. The electrolysis instead produce already very fine iron-powder.

kclo4 - 29-12-2004 at 02:51

fe2o3 + 2al = 2al2o3 + 2fe

neutrino - 29-12-2004 at 06:21

That's the thermite reaction.

rift valley - 29-12-2004 at 06:40

The iron produced in a thermite reaction is always very contaminated with Aluminum oxide.