Although thermodynamically feasible in practice magnesium metal is not used for the reduction of alumina. Why?

Although thermodynamically feasible in practice magnesium metal is not

1.	Although thermodynamically feasible in practice magnesium metal is not used for the reduction of alumina. Why?
Answer» Magnesium can reduce alumina at the temperature above the intersection point of the curves for Al₂O₃ and MgO in the Gibbs Energy vs T plot (Ellingham diagram). But the temperature at which this is feasible is too high to be achieved economically and is also technologically difficult. So this reduction is not done.