In Goldschmidt reaction, certain metallic oxides are reduced to the metallic state by heating with:

${\text{2Al\hspace{0.17em}\hspace{0.17em}+\hspace{0.17em}Fe}}_2{\mathrm{O}}_3\mathrm{\hspace{0.17em}}\to \hspace{0.17em}\hspace{0.17em}{\mathrm{Al}}_2{\mathrm{O}}_3\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}+\hspace{0.17em}\hspace{0.17em}2\mathrm{Fe}\mathrm{\hspace{0.17em}};\hspace{0.17em}\hspace{0.17em}\mathrm{\Delta H}=-\mathrm{ve}$

The heat given out is used in welding. This is also called Gold Schmidt at aluminothermic process.