Sadoway/Allanore carbon-free metal reduction research

Ellingham-diagram thermodynamic argument that any oxide can be reduced by carbon at sufficient temperature, but CO2 externalities are driving MIT research toward electron-based reduction routes.

Anyway, the point is asbestos and things like that become unacceptable over time, socially. Environmental: carbon-free metal reduction. If you look at the free energy diagrams — which I happen to have here — every metal on the periodic table can be reduced from its oxide using carbon if you go to a high enough temperature. [Tom opens a thermodynamics textbook to an Ellingham diagram.] This is the fifth or sixth edition; this is an Ellingham diagram — free energy of formation versus temperature. The free energy of formation increases for every metal on the periodic table. I used to base final exams on this diagram. You'll see that the free energy of formation increases for cobalt and iron, and you can see which ones are more stable — down here you've got aluminum and calcium. But notice this carbon plus oxygen going to carbon monoxide has a negative slope. That means carbon monoxide, if you go to a high enough temperature, will eventually become lower than the free energy of formation of any of the other oxides on the periodic table, and therefore if you go to high enough temperatures any metal can be reduced from its oxide to the metallic form using carbon.