Characterisation of structure of iron ore sinter and its behaviour during reduction at low temperatures

Abstract

METHODS, MATERIALS, AND EQUIPMENT Production of sinters in pilot sintering unitVarious sinter microstructures were produced in the laboratory using the same iron ore blend, Sinters with various mineralogical constituents were provarying only the sinter basicity and the carbon duced in the pilot sintering unit of Usiminas, starting with content of the blend via limestone and coke a basic sinter mix and varying the coke and CaCO 3 peradditions, respectively. The sinter cakes were centages, thereby bringing about changes in the thermal level subjected to low temperature, size degradation and basicity of the sinter. 1 1 ,1 2 In all sinters, the volume of tests and their structural composition was slag (CaO+SiO 2 ) was maintained constant by the addition determined. A relationship has been established of quartzite. The variables in the types of sinter produced between sinter structural composition and its size were determined on the basis of a study of the Fe 2 O 3 -CaOdegradation under low temperature reducing SiO 2 phase diagram and other investigations in respect conditions. Also, varying the gas composition led to of the formation of diVerent phases during the sintering development of a new reduction test procedure, process. 1 3 -1 5 which is more sensitive to microstructural Furthermore, the Al 2 O 3 and TiO 2 contents of the sinter variations than the conventional standard test were varied by additions of bauxite and ilmenite to the (reduction degradation index, RDI).I&S/1574 basic sinter mix, to study the eVect of these components on the reduction degradation behaviour of the sinters.

Reduction Disintegration Behavior of Lump Ore in COREX Shaft Furnace

“…[4][5][6][7][8] However, the reduction conditions in blast furnace were very different with that of COREX shaft furnace, the physical properties and microstructures of lump ores were also different with sinter. All these factors would influence the disintegration behaviors of lump ores in COREX furnace.…”

“…[3][4][5] The disintegration of iron ores mainly occurs during the reduction process from hematite to magnetite in the temperature zone of 400°C-700°C, and some researchers indicate that the main reason for the disintegration is the stress concentration caused by the volume expansion of magnetite. [6][7][8][9][10] But these studies mainly focus on the disintegration behaviors of iron ores under the blast furnace conditions, especially for sinters and pellets. [11][12][13] However, compared with the blast furnace process, the residence time of iron ores in the low temperature zone of the COREX shaft furnace is much longer, and the CO and H 2 proportion in reducing gas of COREX shaft furnace is also quite higher.…”

Study on Reduction Kinetics of Iron Ore Sinter Using Coke Dust

“…Increasing CaO/SiO 2 ratio and oxygen partial pressure have positive impact in favour of the formation of SFCA phase [9][10][11][12][13]. Andrews et al [14] [16,17].…”

Mineral 4/Recognition 4: A Universal Optical Image Analysis Package for Iron Ore, Sinter and Coke Characterization

“…Correct characterisation of iron ore sinter mineralogy and porosity is therefore very important for optimisation of the sintering process and understanding sinter quality in terms of mechanical strength and reducibility [17,18].…”