Sciencemadness Discussion Board

Making iron phosphide without elemental phosphorus?

Merryp - 29-12-2019 at 19:33


I was wondering whether there's a convenient method.

Carbothermal reduction of iron phosphate? (what temperatures would that require?)

Maybe heating P2O5 with iron powder?

Tellurium - 30-12-2019 at 13:12

Well it is possibe to reduce Calcium phosphate(other phosphates should be usable too) with elemental carbon at high temperatures to elemental P. I thing somewhere on youtube I also saw a video using Al as reducing agent. I think using a mixture of phosphate, C and Fe with the absence of oxygen might work. But note that very high temperatures are needed(e.g. a muffle furnance or something similar).

Merryp - 3-1-2020 at 04:11

Quote: Originally posted by Tellurium  
Well it is possibe to reduce Calcium phosphate(other phosphates should be usable too) with elemental carbon at high temperatures to elemental P. I thing somewhere on youtube I also saw a video using Al as reducing agent. I think using a mixture of phosphate, C and Fe with the absence of oxygen might work. But note that very high temperatures are needed(e.g. a muffle furnance or something similar).


That's why I was wondering whether P2O5 would be a more convenient source, given the enthalpy of formation.

Fery - 4-1-2020 at 03:17

Quote: Originally posted by Merryp  
That's why I was wondering whether P2O5 would be a more convenient source, given the enthalpy of formation.

check P2O5 b.p.

Boffis - 4-1-2020 at 07:30

Could you use an alumothermic thermite type reaction with anhydrous FePO4? The latter is easily prepared if you have a ferric salt and a phosphate salt. Iron phosphide is given as Fe3P so you would need to add some iron filling to the mixture which might chill the reaction too much and prevent the reaction being self sustaining. You could use a mixture of iron phosphate and say magnetite;

3FePO4 + 6Fe + 8Al = 3Fe3P + 4Al2O3

The aluminium oxide would be inert to most reaction and the melting point of the phosphide c 1100 C is possibly low enough to get away with it. With magnetite it would be:

9FePO4 + 6Fe3O4 + 40Al = 9Fe3P + 20Al2O3

You could also use red iron oxide. I can see a few experiments might be required but hey, isn't that what we are here for? :)

BromicAcid - 4-1-2020 at 08:25

Quote:
...and R.A. Brooman heated a mixture of silica, iron, coal, and calcium phosphate so as to form a fusible slag and iron phosphide. The latter when heated with sulphur, hydrogen sulphide, carbon disulphide, etc., furnished phosphorus.

Inorganic and Theoretical Chemistry: pg 740

bluamine - 18-4-2022 at 03:52

Quote: Originally posted by Boffis  

9FePO4 + 6Fe3O4 + 40Al = 9Fe3P + 20Al2O3

You could also use red iron oxide. I can see a few experiments might be required but hey, isn't that what we are here for? :)


Wow that's superinteresting!
Did anyone try it yet?