Characterisation of iron ore sinter and its behaviour during non-isothermal reduction conditions

Abstract

Egyptian iron ore sinter with low contents of barite (0 . 5 wt-%BaO) and alumina (0 . 7 wt-%Al 2 O 3 ) was prepared by the down draft sinter pot technique and physically and chemically characterised. The sinter is mainly composed of unassimilated hematite, precipitated hematite and magnetite phases and glassy calcium silicate (slag). Manganese was concentrated in magnetite phase forming a solid solution of 'magnetite-jacobsite spinel'. Calcium ferrites were not detected in the sinter due to its low basicity (CaO/SiO 2 <1). The sinter was non-isothermally reduced with carbon using a heating up reduction technique with the facility of following the high temperature phenomena during the reduction process. High temperature properties were determined from the results of X-ray observations, reduction rate profile and the gasification rate. The results obtained indicated that the reduction of sinter started at 823 K, then at .1073 K and the reduction rate increased due to the interaction between the carbon gasification and gaseous reduction processes. The retardation reduction, smelting reduction and meltdown of metallic iron phenomena occur at 1323, 1473 and 1680 K respectively, which simulate the high temperature region of the blast furnace for iron production.

Migration and Reaction Mechanism of Barium in BaSO4–CaCO3–Fe2O3 System during Sintering

“…[1][2][3] Excellent properties of sinter are the premise of stable operation of blast furnace, which is not only related to the content of main gangue elements such as CaO, SiO 2 , MgO, Al 2 O 3 , but also related to the content of trace components such as BaSO 4 . [4,5] The iron ores mined from Jingtieshan Iron deposit in Gansu Province, [6] Bayan Obo Iron deposit in Inner Mongolia, [7] and Baharia iron deposit in Egypt [8] all contain a certain amount of barite. Since barium and calcium belong to the same main group and have higher optical basicity, it is difficult to remove barite in ore powder due to the reasons of veins; the presence of barium has a certain impact on the formation of sinter bonding phase and metallurgical properties in the sintering process.…”

Investigation of the Reaction Kinetics of a Sinter-Reduction Process in the Thermal Reserve Zone of a Blast Furnace Using a Modified Sectioning Method

“…The coupling reaction among coke, CO, CO 2 , and iron oxides exist during sinter reduction in the thermal reserve zone of blast furnaces [16][17][18][19]. During reduction of iron oxides, the oxygen atom from iron oxides and carbon atom from coke generate CO and CO 2 .…”

Reduction Behavior of Aluminate Calcium Ferrite (CFA) in CO‐N2 Atmosphere

“…As Kalenga and Garbers-Craig [15] reported, increasing alumina contents in the sinter results in a drastic deterioration of its chemical and physical properties and increased concentration of the SFCA phase. Hessien et al [16] found that non-isothermal reduction of sinter samples can be carried out using a heating reduction technique with the facility of following up the high-temperature phenomena during the reduction process. No more than 2.5% alumina increases the reduction rate at the initial stage up to 1073 K, and the reduction rate increases with increasing alumina content of up to 2.5%.…”