Abstract
The problem of contamination has become the centre of interest in the technique for the preparation of a high-purity powder, especially the milling process of the starting powder in high performance ceramics. In this report, the increasing tendencies in the amount of impurity in TiO2 powder during wet alumina ball milling are described.
The results obtained are summarized as follows:
(1) Impurity (intermixture into the ground TiO2 powder), caused by wear of the grinding ball and the mill liner, was mainly included in the finer size range of the ground productt in the initial grinding stage. Also, the size of intermixture was distributed widely throughout the full size range of the ground product in the final grinding stage.
(2) The intermixture concentration was influenced considerably by the viscosity and the specific gravity of the slurry.
(3) The size of the wear debris was distributed into a finer size range of the ground product. Then, in the closed circuit wet milling process, it was estimated that the impurity was concentrated in the fine grinding product that was collected by the classifier.
