A finite difference model of the iron ore sinter process
J Muller, TL de Vries, BA Dippenaar, JC Vreugdenburg
Iron ore fines are agglomerated to produce sinter, which is an important
feed material for blast furnaces worldwide. A model of the iron ore
sintering process has been developed with the objective of being representative
of the sinter pot test, the standard laboratory process in which the
behaviour of specific sinter feed mixtures is evaluated. The model aims to
predict sinter quality, including chemical quality and physical strength, as
well as key sinter process performance parameters such as production rate
and fuel consumption rate. The model uses the finite difference method
(FDM) to solve heat and mass distributions within the sinter pot over the
height and time dimensions. This model can further be used for
establishing empirical relationships between modelled parameters and
measured sinter properties. Inputs into the model include the feed material
physical properties, chemical compositions, and boundary conditions. Submodels
describe relationships between applied pressure differential and
gas flow rate through the bed of granulated fine ore particles, combustion
of carbonaceous material, calcination of fluxes, evaporation and condensation
of water, and melting and solidification. The model was applied to
typical sinter test conditions to illustrate the results predicted, and to test
sensitivities to parameters such as feed void fraction, feed coke
percentage, and the fraction of combustion heat transferred to the gas
phase. A model validation and improvement study should follow, ensuring
sinter test results are free from experimental errors by conducting repeated
tests.
Keywords: iron ore sintering, finite difference method, coke combustion, calcination,
evaporation and condensation, melting and solidification, sinter strength.