Journal of the Southern African Institute of Mining and Metallurgy
On-line version ISSN 2411-9717
MULLER, J.; DE VRIES, T.L.; DIPPENAAR, B.A. and VREUGDENBURG, J.C.. A finite difference model of the iron ore sinter process. J. S. Afr. Inst. Min. Metall. [online]. 2015, vol.115, n.5, pp. 409-417. ISSN 2411-9717.
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.