Numerical simulation of the effect of sulfide concentrate particle size on pollutant emission from flash smelting furnace

Abstract

In this research, numerical simulation of three-phase flow (airflow, sulfide concentrate particles, and liquid fuel droplets) within a copper flash smelting furnace was conducted to investigate the effect of combustion of the sulfur present in the sulfide concentrates on temperature distribution and species production. The effect of sulfide concentrate size, amount of sulfur present in concentrates and air enriched with oxygen on sulfur combustion were numerically analyzed. The simulation was conducted using the Eulerian method for the continuous phase and the Lagrangian approach for discrete phases. The probability density function and the renormalization group K-epsilon model were used for combustion modeling and simulation of turbulence effects on the rate of chemical reactions. The discrete ordinate method was used to calculate the effect of radiative heat transfer. Results showed that when the amount of sulfur present in the concentrate particles increases, a higher level of sulfur release leads to an increase in the concentration of SO2, SO3, and SO. Also, by decreasing the concentrate particle size and increasing the rate of heat transfer to the particles, the amount of sulfur released increases. Since sulfur combustion occurs by high radiation, an increase in the sulfur released makes the temperature distribution more uniform within the furnace. Besides, by increasing the sulfur released, the concentration of CO2 decreases because gasoil competes with sulfur for oxygen consumption. Finally, it has been revealed that the amount of all species such as SO2, SO3, SO, CO2, and NOx, and the temperature increase using air enriched with oxygen.