Influence of process parameters on zinc powder produced by centrifugal atomisation

Abstract

An experimental centrifugal atomiser was used to study the manufacture of zinc powder. Melt temperature, melt flow rate, rotating speed and diameter of the atomising disc, are operating parameters that were varied, and their effects on powder quality and yield were observed. The median particle size and the particle size distribution tended to be better, i.e. smaller and narrower, with increasing rotating speed, melting temperature, and atomising disc size. With decreasing melt flow rate, the median particle size decrease and the particle size distribution is similar, all curves are almost overlapping. The yield of zinc powder increased with rotating speed and disc size, and decreased with melt flow rate. Apparent densities of zinc powder were in the range from 1.65 to 2.51 g/cm3. In SEM micrographs most zinc particles were irregular in shape, and the particle structure was mainly cellular based on optical imaging after etching of a polished surface.