Preparation of nanosized zinc oxide by vacuum oxidation and behaviors of impurity elements

Nanosized zinc oxide with the purity ≥99.98 was prepared with a vacuum oxidation method based on hot-dip galvanizing slag by using air as the oxygen source. The effects of reaction temperature and vacuum degree on the product morphologies were investigated, and the influences of main impurity elements in raw materials on the quality of products were evaluated under different oxidation conditions. Reaction temperature arid vacuum degree dramatically affect the product morphologies. At appropriate temperature and vacuum degree, the main products are wurtzite crystals. The crystal needles are elongated and long in length. Impurity Fe and Pb elements influence the quality of products through various patterns under different oxidation conditions. Fe remains in the products mainly relying on the mechanical entrainment of Zn vapor and the positive deviation of Fe-Zn system, while Pb is retained mainly based on the vapor pressure and the positive deviation of Pb-Zn system.