Dissolution Rate of Lead(II) Oxide in an Equimolar KCl-PbCl_2 Melt

摘要

Dissolution rates (W) of lead(II) oxide in a KCl-PbCl_2 equimolar melt are determined experimentally using the gravimetric method at T = 773, 823, and 873 K. It is shown that, as the temperature increases from 773 to 873 K, the initial magnitude of ^increases from 23.9 to 45.6 mg/(cm~2 min) with a conventional roughness coefficient of 10. Then the values of W for all temperatures are leveled, being close to zero after 25 min, which indicates the diffusion mode of the process in natural convection conditions. The activation energy of the interaction between PbO and the KC1-PbCl_2 melt was 37.370 ±0.118 kJ/mol. The limiting concentration of PbO in the equimolar KC1-PbCl_2 melt was determined, being 9.1, 10.6, and 13.5 wt % at T=773, 823, and 873 K, respectively.