STUDY OF THE EFFECT OF EXPERIMENTAL 70%-IRON CONCENTRATE ON TECHNOLOGICAL PERFORMANCE INDICATORS AND SINTER QUALITY

Abstract

One of the main functional properties of iron-ore sinter is iron content, which mainly determines the technical and economic parameters of iron production. Metallurgists are ever striving to increase the iron content in sinter. At present, the majority of Russian steelmakers produce sinter from concentrates with iron content of 65‒66%. OJSC Stoilensky GOK has been searching for new enrichment methods to increase iron content in the iron ore concentrate, and it has managed to obtain an experimental concentrate containing 70% iron. Studies conducted in Japan have shown that the productivity of sintering machines deteriorates when the iron content in concentrate rises and the SiO2 content lowers. With increasing iron in sinter, Russian scientists have established a decrease in strength and higher breaking. This required further study, so research was conducted to determine how partial and full replacement of the current iron-ore concentrate with experimental concentrate (70 % Fe) in sinter charge influences technological parameters and sinter strength. Increasing the share of experimental concentrate in sinter charge causes increase in iron content in sinter and decrease in SiO2 content. With this, metallurgical value of sinter goes up, while strength, yield of good sinter, productivity of sintering machines and sinter strength deteriorate. The main reason for the reduction in strength is the reduced amount of melt during the sintering of charge. As a result, the sinter cake structure gets areas of poorly sintered charge material, and vitreous phase is found in the binder along with strong ferrites. These factors are the main drivers of sinter strength reduction observed when the share of experimental concentrate in the charge increases.