A mixture of alumina (Al 2 O 3 ) and zircon (ZrSiO 4 ) was subjected to mechanical milling. The presence of alumina was found to greatly enhance the disordering of zircon. Acid leaching of the milled oxide mixtures resulted in complete dissolution of the zirconium, along with a proportion of alumina and only traces of silica. Zirconium leaching was not possible with zircon milled alone. Quantitative results of the leaching process are given.