4. Conclusion

It has been demonstrated that a simple dissolve method using HCl or NaOH which was reacted with a mono- or bi-cationic metals or with a natural mineral can be accomplished to produce high-purity, nanocrystalline metal oxide ceramics. Pure MgO, TiO2, MgTiO3, and ZrSiO4 nano-powders were produced by the method. The main step for the metal case was on the formation of the precursor and appropriate calcination temperature. For the mineral case, purification of the phase under consideration by reacting the contaminating phase with acid or base, followed by filtering, washing, and calcination, was the key of the process.
