How would you separate a mixture of Zinc Oxide (ZnO) and Manganese (III) Oxide (Mn2O3), without using concentrated acids?

Firstly, Add 4 M NaOH to the mixture. ZnO in the mixture dissolves, but Mn₂O₃ does not.
ZnO(s) + 2NaOH(aq) + H₂O(l) → Na₂[Zn(OH)₄](aq)
Then, filter the mixture. Wash the residue (Mn₂O₃) with distilled water and dry in an oven. Mn₂O₃ is obtained.

Dilute the mixture with a plenty of water, and Zn(OH)₂ precipitate is formed.
Na₂[Zn(OH)₄](aq) → 2NaOH(aq) + Zn(OH)₂(s)
Filter the mixture. Wash the residue (Zn(OH)₂) with distilled water.

Strongly heat the Zn(OH)₂, and ZnO is obtained.
Zn(OH)₂(s) + heat → ZnO(s) + H₂O(g)