Study on the evaporation kinetics of zinc and lead in Zn-Pb-bearing dust pellets mixed with coal powder

The study on the evaporation kinetics of zinc and lead in the pellets made of Zn-Pb-bearing dust mixed with carbon, in nitrogen atmosphere at the temperature range between 1 100 degrees C and 1 300 degrees C , shows that the reduction temperature has a significant effect on the evaporation rates of zinc and lead and that both the particle size of coal powder and the extra carbon content have no effect on the evaporation rates. The obtained activation energies for the evaporation of zinc and lead are 79. 42 kJ/mol and 88. 74 kJ/mol respectively. The evaporation rate of zinc is controlled by the reaction between zinc oxide and CO while that of lead is controlled by lead volatilization and the diffusion of gaseous lead through gas boundary layer covering the surface of liquid lead.