Extended Analyses of Iron Ore Sinter by Image Processing

The iron ore sinter quality is described by various parameters. The mineralogical and textural characteristics are obtained by image processing from microimages of polished sections. The image processing software VisuMet is adapted to analyze the mineral abundance and porosity of iron ore sinter. New algorithms are developed to calculate microstructural characteristics, like the pore size distribution and the effective thickness of sinter grains. The validation of the method using image processing is given by the description of three test series to estimate the systematic and analytical errors. The application to five industrial sinter samples is outlined. Ninety percent of all pores are smaller than 250 μm in equivalent diameter and the mean equivalent diameter ranges from 76 to 79 μm. The effective thickness, which is defined as the maximum distance between solid and nonsolid sinter material, varies between 120 and 368 μm. The area degradation algorithm of VisuMet is used to calculate the gradient between 30% and 80% of the degraded area. Dense sinter grains have a lower gradient than porous ones.