Intensification of the removal of iron impurities from microporous aluminum oxide via argon blowing

A model is proposed for intensification of the process of high-temperature vacuum removal of iron impurities from microporous aluminum oxide via purging of the particle layer with argon. In the temperature range characteristic of this process, the pressure of saturating vapors above pure iron is on the order of $0.1$ mm Hg. For an impurity with a concentration of several particles per million, the figure is proportionally smaller, and this creates problems with evacuation of the chamber. The use of argon as a carrier gas destroys the rigid connection between the partial vapor pressure of the impurity and the pressure in the vacuum chamber. Calculations show that the argon flow under moderate vacuum $10^{-5}$ mm Hg with a mass flow rate on the order of $10^{-7}$ kg/(m$^2$ s) provides a very deep purification.