Sciencemadness Discussion Board

Quick oxydation of Iron powder

Elhuyar - 12-2-2024 at 08:30

Hello everybody


From long time ago I am trying to make some amount of hydrated iron oxide, call it FeOOH or goethite... Among other systems , like Massart precipitation or electrolysis, I thought that simple oxidisation to rust in salty aerated water would work fast, in a matter of days.

Everybody knows that hand heaters have iron powder, salt, GAC and some fibers and that that reaction is quick and exothermic, supposedly yielding iron oxide

But when I try to quickly get this rust, nothing happens, neither direct powder oxidation nor oxidation of kind of hand heater mixture.
This is a mistery. Some say that the powder is not enough small, but I doubt it.

Thanks in advance!

DennyDevHE77 - 12-2-2024 at 08:42

FeOOH is iron methahydroxide. If you need it, buy iron sulfate from a horticultural store, make a saturated solution, and pour baking soda into it until the foam stops.

FeSO4+2NaHCO3=FeCO3+Na2SO4+H2O+CO2

After that, pour the crushed hydroperite tablets into the reaction mixture. Or pour perhydrol (37% hydrogen peroxide solution, although I think almost any concentration will do). And add it again while the foam is on.

2FeCO3+H2O2=2FeOOH+2CO2

Then comes the settling and washing of the sediment.

If you calcinate the precipitate at 300-350C, the iron metahydroxide will turn into Fe2O3.

Hydroperite is a clathrate of hydrogen peroxide with urea (Hyperol, artizone, urea hydrogen peroxide).

Elhuyar - 13-2-2024 at 00:37

Many thanks.

I disregarded the methods of precipitation with alkali because I have always to get rid of the salts, Na2SO4 or NaCl by washing, prior to filtering.
And especially because I have a lot of iron and steel scrap.
I wonder why direct rusting is not more frequently used. No need of chemicals.

Sulaiman - 13-2-2024 at 11:38

Iron wool scrubbing pads and iron powder rust fairly quickly when moist and exposed to air,
submerged in water iron rusts more slowly due, I think, to the low solubility of oxygen in water.
I'd try adding H2O2 to the mix to see if it helps.

DraconicAcid - 13-2-2024 at 11:54

I'm pretty sure you can burn iron wool using a Bunsen burner or a 9-volt battery.

Elhuyar - 13-2-2024 at 14:37

Quote: Originally posted by Sulaiman  
Iron wool scrubbing pads and iron powder rust fairly quickly when moist and exposed to air,
submerged in water iron rusts more slowly due, I think, to the low solubility of oxygen in water.
I'd try adding H2O2 to the mix to see if it helps.


I think that's the key point, submerging in water limits the available oxygen, so just wet powder is better, but then it's more difficult to shake the powder...but the heating pads just need to be pressed to add the water...

Laboratory of Liptakov - 15-2-2024 at 05:06

Maybe is possible use for oxidation the iron wool the Liptakov universal converter.
https://www.youtube.com/watch?v=ERevYEszAwo
Medium can be normal water, better will distill water with add H2O2 3- 10%.
Also you can create saturated NaCl solution + 10% H2O2. It works in Liptakov converter. Confirmed.


[Edited on 15-2-2024 by Laboratory of Liptakov]

Elhuyar - 16-2-2024 at 00:54

Quote: Originally posted by Laboratory of Liptakov  
Maybe is possible use for oxidation the iron wool the Liptakov universal converter.
https://www.youtube.com/watch?v=ERevYEszAwo
Medium can be normal water, better will distill water with add H2O2 3- 10%.
Also you can create saturated NaCl solution + 10% H2O2. It works in Liptakov converter. Confirmed.


[Edited on 15-2-2024 by Laboratory of Liptakov]


I see that for iron the Liptakov idea is FeCl3 + Fe (0) + NH4OH. To yield a kind of Fe(OH)3 or FeOOH. But with just FeCl3 + NH4OH you get that.

Etanol - 16-2-2024 at 01:53

Electroliz works faster.
10-15% NaCl solution,U=3...5V, Fe or steel as anode (+).
Fe+2H2O=>...=>Fe(OH)2+H2
then on air Fe(OH)2=>FeO(OH)

Laboratory of Liptakov - 16-2-2024 at 02:28

Of course, most efficiency is eletrolizer
https://www.youtube.com/watch?v=8ZQ67POLiqg

Elhuyar - 18-2-2024 at 14:54

Quote: Originally posted by Laboratory of Liptakov  
Of course, most efficiency is eletrolizer
https://www.youtube.com/watch?v=8ZQ67POLiqg


Yes, I tried it. It gives a kind of black magnetite rather than the mentioned Fe(OH)2, that needs , yes, some oxidant to go to goethite.

Rainwater - 18-2-2024 at 17:42

7 days ago I put an aquarium air bubbler into a 2liter bottle stuffed with 450g of steel wool and 1 liter of di water.
Topped it off to 1l mark every day, almost 100ml a day lost.
Yesterday there where some chunks left. Today its all been converted to red rust.
Stuff makes for a nice clay base.