Thread: How To Make 100% Pure Rust

I'm trying to figure out how to make pure rust (Fe2O3). Using electrolysis in salt you can make rust, but you also get some Iron (II) Hydroxide which makes it impure- how do I know this, I tried it and my solution looked like this: File:Ferrous hydroxide.JPG - Wikipedia, the free encyclopedia so I'm certain it's impure. Putting Iron in water and just waiting also makes pure rust but it takes a long time. I tried burning iron wool with a 9 volt battery but it didn't turn it into rust (it turned it more grey), I might be able to make it rust by getting a source of pure oxygen near the flaming wool and letting it rust, but I don't have the equipment for a really complicated setup. Can anyone think of an ingenious and simple method to create pure rust in relatively short period of time?

The best method is ask an old friend that lost the lot

I don't get it

I guess not don't tell you old friends they might have forgot I might research the answer but that's like boring.

Think Metal Heads

First, you need to tighten up your terms. Rust and Fe₂O₃ (ferric oxide or iron(III) oxide) are not quite the same. Rust is an ill-defined term. It is essentially hydrated ferric oxide. And the Wiki reference you gave for ferrous hydroxide is a compound that is normally found in rust.

So you need to make up your mind. If you are trying to make rust, then it should properly contain some ferrous hydroxide and still be rust. But if you are trying to make pure ferric oxide then you need to go about it differently.

From Wiki, iron (III) oxide is a product of the oxidation of iron. It can be prepared in the laboratory by electrolyzing a solution of sodium bicarbonate, an inert electrolyte, with an iron anode:

4 Fe + 3 O₂ + 2 H₂O → 4 FeO(OH)

The resulting hydrated iron(III) oxide, written here as Fe(O)OH, dehydrates around 200 degrees C.

2 FeO(OH) → Fe₂O₃ + H₂O


OK now?

Yea, I get it now, I was actually going to try sodium bicarbonate as a catalyst today. I assume it will be hard to filter it from the Iron Oxide, any idea how I should go about doing that? I was thinking of just getting a coffee filter and letting the solution settle the rust on it and hopefully allow the sodium bicarbonate + water solution to slip through, any idea if this will work?

Yes, you have the right idea. Use filter paper to catch the ferric oxide and to remove the sodium bicarbonate solution. Then rinse a few times with distilled water to remove final traces of it. You should be left with hydrated ferric oxide. Heat it up to 200 degrees C and you have pure ferric oxide.

What's the idea of creating rust? Does it bring some kind of authentic touch to a car, bike or theme park?

If there is salt water in the ocean and the ship sinks for 80 years how can salt water have the properites of pure sodium?

Ok so I used sodium bicarbonate as the catalyst but I still don't have pure rust, I have two different substances that form a layer (I believe Iron III Oxide is on the top layer) and a black substance which I'm not sure what it is on the bottom layer (it might be Iron Oxide), I uploaded some pictures to help illustrate what I see: Image hosting, free photo sharing & video sharing at Photobucket .
Some conclusions I drew:
Bottom substance must be heavier or form a more dense crystalline structure than the top layer.

Either sodium bicarbonate is not an inert catalyst or there is some other substance in the water that is reacting to create two separate substances (I know water has some chemicals like fluoride in it but that doesn't account for the relative equal mass of the two substances that have formed).

Three questions, what should I do to get pure rust? What are the two substances that formed? If the bottom layer is Iron Oxide can I simply heat that up to get Iron III Oxide?

go buy some, its cheap

That's not the point, I want to know how it's made, what do the people selling it do to make it pure?

Would it work to stick an electromagnet in the solution?

Ahahaha funny you ask because that was one of the first methods I tried (I had an electromagnet but I found it easier to just use a permanent magnet with aluminum foil wrapped around it and then remove the foil to take the rust off). And it doesn't work unless you can grind the rust down to a molecular level and even then you still won't get perfectly pure Iron (iii) Oxide, and even still the Iron Oxide Hydroxide is magnetic too so it will stick to the foil as well.

Get some ferrous sulfate crystals and heat them in a fume cupboard. Water plus SO2 and SO3 comes off leaving nothing but Fe2O3.

If I'm gonna go buy ferrous sulfate crystals I might as well go buy Iron III Oxide instead, unless you know of a household item that cant be turned into ferrous sulfate crystals easily. Is there really no way to get pure Iron III Oxide from iron? I thought for sure some chemist somewhere would know how to make such a simple chemical easily.

Then get some iron and dissolve it in sulfuric acid to get your ferrous sulfate.

Ok, I could get some sulfuric acid from a car battery, but it's still a really dangerous method to make rust, isn't there a simple way using electrolysis? Also do you have any idea why there are two substances being formed when I try to make it with sodium bicarbonate?

It's quite confusing and as a fact nothing can be done 100%

well I mean they sell the stuff at art stores at nearly 100% pure, what's their method. Seems like no mater what I do I get Ferrous Oxide Hydroxide.

This peeked my curiosity... why would you want to make that stuff anyway?

You've just peaked my curiosity, why do you care?

Well thats the thing, I don't.

Great, then we'll get along just fine and dandy.

So... i cant be curious and wondering why you would want to make pure rust, of all things you could create. I thought it might be for a school assignment or something. No reason to act so buthurt about it.

You derailed my entire conversation!!! I'm butthurt because this wasn't a post designated for why I wanted to make rust you could have PM'd me I would of told you, and now I can't delete any of your comments.

We.., you could have answered directly without acting up like that. Would have resulted in less unrelated comments from my part :P
Anyway, have you tried making the rust and then filtering the unwanted compontents out afterwards? It might be easier... not sure though.

Yea I thought about that, I made a buchner flask out of a bicycle pump and some empty peanut butter jars to filter out the solid products from the liquids, but I don't know of a method to filter two solids from one another.

I'm not sure about this but I assume I might be able to use a centrifuge to do that but I don't know enough about it to try.

you got several answers
lab prep is electrlysis of sodium bicarb- iron electrodes
heat resultant to 200C
now go get your nails, penutbutter jars, battery, bicarb, get to work and quit pissn' an moaning

dude, if you read the post you would have seen that I did do it, and I got two products in the solution meaning its not pure, here are the pics:
Image hosting, free photo sharing & video sharing at Photobucket

Sodium bicarbonate--no salt. READ!

I did it with pure sodium bicarbonate as a catalyst. I didn't use salt. The pictures I posted are the result of that.

Hohohohoho...new information for me. I like this, bookmark this page. chemistrylessonsonline.com

I would say that the greenish black layer is fine and filter out the excess water and let it dry you will get red iron oxide, NaHCO3 is an electrolyte and not catalyst. Do not use NaCl as it liberates harmful Cl2 gas,NaHCO3 will release CO2 and hydrogen.so gud luck,also the salt used will filter out on filtering when on mixing salt in water, make sure All of it dissolves

You could try iron filings in lemon juice or vinegar. Leave them sit a few days, then drain off and evaporate the water in air then heat up the citrate or acetate to decompose it to FeIII oxide.