Is there a level of decomposition after rust? Or is there any way (either naturally or through processing) to return rusted iron to a deoxidized state?

Question

From my understanding, iron veins in mines are spotted by their bright red color due to rust on the exposed surface. Then when it’s refined, the rust separates as slag and is discarded, leaving the pure iron behind.

Is this accurate? Or does the refining process deoxidize iron while separating impurities?

In: 16

Answer 1

Decomposition is the wrong word, because the iron is just fine.

Also all of the iron you mine is rust. Not just the surface.

You just break down the rocks the iron ore is found in, and heat them with something that will want the oxygen from the oxidised iron more than the iron. Usually that’s carbon.

And carbon and oxygen gives carbon oxides, which just leave as gasses. Thus the slag is solely the accompanying rocks in the material you mined.

If you smelted pure ironoxides rather than iron ore, there would be no slag.

Slag is just molten rock, mostly silicates, a similar to glass.

Basically all iron in the ground has at some point been oxidised. We mine the rocks that contain that oxidised iron, and then use carbon to separate the oxygen and iron.

So no iron can’t rust further under natural circumstances. However you can react rust with stronger oxidants than oxygen like fluorine, and then get oxygen gas and iron fluorides, this doesn’t happen naturally though, cause there no free fluorine gas around.

Rust IS iron. Just a salt of iron.
The slag has nothing to do with being part of the rust. It’s just the rocks you found the rust veins in.