A dynamic simulation of a lead blast furnace

Abstract

A dynamic model has been developed to simulate the operation of the stack zone of a lead blast furnace. The mathematical formulation of the governing equations of change leads to a system of 2nd order partial differential equations, which is solved by finite difference methods. A reduction model of ash-layer diffusion controlled mechanism, which allows the stepwise reduction to the lowest oxide or metal thermodynamically possible for the local gas composition within the sinter, is employed in this model. The surface reaction and the internal diffusion in the porous solid particles are taken into account in the coke gasification reaction. The profiles of the temperatures of gases and solids, solid compositions, and gas compositions and pressure in both radial and axial directions are predicted by the model. The results provide a good representation of the experimental data obtained for the blast furnace at Brunswick Mining and Smelting Corp., Ltd., New Brunswick, Canada and also of the less extensive data available for the Cominco blast furnace at Trail, British Columbia, Canada. In addition to the modelling of the stack, a mass and energy balance for the bosh zone is also included in the present calculation. The improvement of coke efficiency due to oxygen enrichment in the blast air for the Brunswick Furnace were interpreted semiquantitatively. The effect of sinter size distribution on the furnace performance has also been studied.