Numerical and analytical simulation of the production process of ZrO2 hollow particles

Abstract

In this paper, the production process of hollow particles from the agglomerated particles is addressed analytically and numerically. The important parameters affecting this process, in particular, the initial porosity level of particles and the plasma gun types are investigated. The analytical model adopts a combination of quasi-steady thermal equilibrium and mechanical balance. In the analytical model, the possibility of a solid core existing in agglomerated particles is examined. In this model, a range of particle diameters (50μm $ \le D_{{\rm p}0} \le 160$ μ m) and various initial porosities ( $ 0.2 \le p \le 0.7$ ) are considered. The numerical model employs the VOF technique for two-phase compressible flows. The production process of hollow particles from the agglomerated particles is simulated, considering an initial diameter of $D_{{\rm p}0} = 60$ μm and initial porosity of $ p = 0.3$ , $ p = 0.5$ , and $ p = 0.7$ . Simulation results of the analytical model indicate that the solid core diameter is independent of the initial porosity, whereas the thickness of the particle shell strongly depends on the initial porosity. In both models, a hollow particle may hardly develop at small initial porosity values ( $ p < 0.3$ ), while the particle disintegrates at high initial porosity values ( $ p > 0.6$ .