A STUDY ON THE EXAMINATION OF THE SINTER METALOGRAPHIC STRUCTURE

Abstract

Sintering process is carried out domestic and imported iron ore powders, fluxes (limestone, dolomite etc.), coke dust, metallurgical recycling powders and slag forming agents. The purpose of the sintering process is to produce a charging material with suitable thermal, mechanical, physical and chemical properties that can be fed into the blast furnace. Nowadays, in order to obtain process and operating parameters that will work with the best sinter quality, extensive researches have been made by iron and steel industry. The sinter quality parameters followed by the sinter blend loaded on the sinter strand and then granulated were examined. In the sintering process, the temperature rises to 1450 oC, partially melting between the sinter grains and a series of reactions take place in the sinter matrix to be charged into the blast furnace to produce liquid crude iron. Many different approaches have been used to estimate sinter quality, to explain the effects of iron ore properties and process variables on sintering mechanisms, and to characterize sinter mineralogy of iron ore. We can obtain chemical analysis of the phases by scanning electron microscopy (SEM) technique, but full consistency with images is not always possible and especially SFCA (silico-ferrite of calcium and aluminium) and SFCA-I phases are difficult to distinguish from each other and future studies are required in this field. The mineralogy and microstructure of the sinter plays an important role in determining the physical and metallurgical properties of the iron ore sinter. Mineralogical characterization of sinter phases; it is a complementary tool to conventional physical and metallurgical tests applied to iron ore sinter to evaluate and estimate sinter quality. Measurement techniques used in this study; optical image analysis and X-ray diffraction (XRD), scanning electron microscopy (SEM), energy distribution spectroscopy (EDS), the results from raw data converted to autoquan format will be explained on the new studies on the interpretation of the Rietveld system. Depending on the measurement objectives of each technique, the quantification of the crystal phases, the relationship between the measurement results, the chemical composition of the phases and the relations between the minerals, as well as their advantages and disadvantages will be explained.