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Full thermal decomposition of metal oxides?

  1. May 14, 2017 #1
    I haven't been able to find much information on the thermal decomposition of metal oxides into their corresponding metals and oxygen. What temperature would Fe3O4 decompose mostly(80%) into its base elements? Additionally, how can this information be determined based upon bond energies/structures for other elements?
    For those who are curious, I am looking into methods for producing metals thermally for use where reducers such as carbon are not present in high enough concentrations to be useful.
  2. jcsd
  3. May 15, 2017 #2
    Check Ellingham diagrams. They provide temperature-oxygen partial pressured regimes for metal oxides. Iron oxides are well-studied. So surely you will find the needed data.

    Direct computations, requires full electronic structure calculations coupled with finite temperature effects. I think there was a paper in Phys. Rev. B journal on this calculation for iron oxide. I can try googling it if you are interested.
  4. May 15, 2017 #3
    Whoops misclicked there. Yeah if you could point me in the right direction for those I would appreciate it. I did look at some of the Ellingham diagrams before but was not too sure about the iron oxides because they seem to run off most of the charts. I will further investigate the paper as well.
  5. May 15, 2017 #4
    This Ellingham diagram contains all the decompositions of iron oxides starting from Fe2O3 through Fe3O4, FeO, and eventually to Fe.


    The paper I mentioned cared more about the transitions in the PO2-PH2O space with little regard to temperature, but it may still be useful:

    An arxiv version of the paper is here:

    The key thing is that the decomposition depends on both temperature and oxygen partial pressure. I hope this helps.
  6. May 15, 2017 #5
    Thank you very much for this! This helps a bunch!
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