Thermodynamic calculations were used to study the dust-forming mechanisms during the copper converting process and to study the possibilities for achieving a controlled dust generation through selective condensation. The evaporation of Zn, Pb, Bi, As and Sb from the melt during the copper converter process and their condensation at decreasing temperatures was simulated. Comparison with experimental data from the full-scale process shows a good qualitative agreement. It was therefore considered possible to use the thermodynamic model to predict the generation of chemical dust in the gas cleaning system at various temperatures and varying amounts of leakage air. A selective condensation of Pb, Zn and As at various temperatures could according to thermodynamic calculations, be possible at high temperatures. A selective condensation of metals requires a closed gas cleaning system or a gas cleaning system with a limited amount of leakage air in order to maintain the desired temperature level.
Godkänd; 1998; 20080328 (cira)