Experimental study on the thermal volatilization and condensation of zinc at 10 Pa and 200 Pa

The thermal volatilization and condensation of zinc at different heating temperatures were investigated at 10 Pa and 200 Pa. The vacuum technique is beneficial for the volatilization of metallic zinc, and the zinc volatilization is affected by heat transfer and mass transfer. The effect of zinc partial pressure on the nucleation is analyzed in terms of the average number of collisions of molecules. When the system pressure is 10 Pa, the range of the condensation temperature of (623-503 K) does not change with the change of the heating temperature, which is consistent with the pressure on the average number of collisions of zinc molecules per unit time. In addition, when argon gas is introduced into the system to keep the pressure at 200 Pa, the condensation temperature ranges becomes different and the heating temperature is linear with the condensation initiation temperature. The condensation mechanism of condensed products is different at different axial distances of 1023 K under 10 Pa and 200 Pa. The morphology and the particle size of the products are different under different system pressures, respectively. (c) 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY -NC -ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).