Numerical Simulation of Transfer Process in Imperial Smelting Furnace

Abstract

The mathematical models, which describe the transfer process in Imperial Smelting Furnace (ISF) of Pb-Zn, were established by means of the rules of metallurgical reaction engineering, mass and energy conservation. These models took into account 4 important chemical reactions, heat and mass transfer between gas and solid. The solid particles were treated as porous media when the diffusion of the gas was calculated. The main parameters, such as temperature, the mass of every species, etc, were measured for an operating ISF, and were used as boundary conditions. Based on the Fortran program language, the code to solve the corresponding govern equations was developed, and thermal processes in the furnace were numerically simulated. The results show that the maximum temperature is about 1870K, which is around 1m from the inlet of primary air. The temperature of gas from the top of burden is about 1300K, which is lower than that in the similar furnace. So, it is necessary to take some means to decrease the heat loss from the wall of ISF. A lot of CO exists in the flue gas, which can be used as fuel of boiler or combustion equipment. Based on the mass flow rate and temperature distribution of gas and burden in ISF, the height of five zones, i.e. preheating zone, PbO reduction zone, ZnO reduction zone, coke gasification zone and coke combustion zone, are respectively 2.0m, 0.6m, 3.8m, 4.0m and 2.5m The predicted results by the model are accordant with the measured values in an operating ISF.