Effect of fluxing agents on the swelling behavior of hematite pellets

Dwarapudi, Srinivas; Banerjee, P. K.; Chaudhary, Pradeep; Sinha, Surajit; Chakraborty, Ujjal; Sekhar, Chandra; Venugopalan, T.; Venugopal, R.

doi:10.1016/j.minpro.2013.11.012

Cited by 38 publications

(9 citation statements)

References 10 publications

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“…Besides, the volume swelling is also related to the ability of slag phase to withstand the reduction stresses of iron oxide particles [22]. Generally, the slag phase with a high melting point would provide sufficient bonding strength to limit the swelling, especially at a higher reduction temperature.…”

Section: Resultsmentioning

confidence: 99%

Effect of MgO addition on the metallurgical properties of the vanadium-titanium pellet with simulating blast furnace conditions

Zhao

Chu

Feng

et al. 2018

Ironmaking & Steelmaking

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MgO addition plays a vital role in improving the quality of pellets. In this study, the effects of MgO addition on the compressive strength, reducibility, reduction swelling characteristics and softeningmelting performance of V-Ti pellets were explored systematically with simulating BF conditions. From the results, it can be observed that the compressive strength decreased with increasing MgO due to the formation of magnesioferrite, the restriction of recrystallization-agglomeration of haematite and the decreasing of molten slag. The reducibility of V-Ti pellets improved substantially due to the increase of the porosity. The decreasing of RSI is mainly caused by the decreasing of lattice volume swelling during the transition from MgO•Fe 2 O 3 to (Mg,Fe)O. In addition, the softening-melting behavior and permeability of V-Ti pellets packed bed was found to be improved with increasing MgO content. In sum, the V-Ti pellets with a MgO content higher than 2.4% exhibits optimum metallurgical properties.

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Section: Resultsmentioning

confidence: 99%

Effect of MgO addition on the metallurgical properties of the vanadium-titanium pellet with simulating blast furnace conditions

Zhao

Chu

Feng

et al. 2018

Ironmaking & Steelmaking

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“…The principal effect of CaO is to form low melting calcium silicate compounds which act as a bonding agent for the iron oxides during sintering (Dwarapudi et al, 2011(Dwarapudi et al, , 2014Friel and Erickson, 1980). The amount of liquid formed in the sintering process of iron ore pellets must be high enough to bond the pellet, but not so much that the pellet core becomes too heavily sintered, pulling away from the shell and leading to cracking of pellets (Firth et al, 2008).…”

Section: Discussionmentioning

confidence: 99%

Effect of adding limestone on the metallurgical properties of iron ore pellets

Iljana

Kemppainen

Paananen

et al. 2015

International Journal of Mineral Processing

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In order to produce high-quality pellets with good reducibility and superior softening and melting properties, certain additives are important. One of the most common fluxing materials for iron ore pellet production is limestone, which is mainly calcium oxide (CaO). In this study, the effect of adding limestone on the metallurgical properties (reducibility, swelling, cracking, softening temperature, Low-Temperature Disintegration, Cold Crushing Strength) of acid iron ore pellets was investigated using a comprehensive set of metallurgical laboratory tests. The dynamic reducibility test under unconstrained conditions showed a higher final degree of reduction in limestone-fluxed pellets compared to non-fluxed ones. Also in the reduction-softening test under load, the fluxed pellets reduced to a higher final degree of reduction, although they started to soften at a somewhat lower temperature. Swelling and cracking of the pellets during dynamic reduction were slightly increased by the addition of limestone, but not remarkably. Adding limestone slightly decreased the Cold Crushing Strength and increased the formation of fines in the hematite to magnetite reduction stage in the LTD test. However, all four parameters (CCS, LTD, swelling, and cracking) are within the acceptable range for blast furnace use.

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“…High-grade lump ores, sinters and pellets are the main furnace burden used to produce pig iron in iron and steel companies. Compared with lump ores and sinters, pellets are considered to have a higher iron grade, uniform particle size and lower coke consumption [1]. The negative impacts of traditional furnace burden on energy resource consumption and environmental pollution concerns have been increasing in recent decades, which stimulated extensive efforts to develop fluxed pellets with better quality and metallurgical properties to replace parts of the sinters and lump ores [2,3].…”

Section: Introductionmentioning

confidence: 99%

Influence of Basicity and Calcium-Containing Substances on the Consolidation Mechanism of Fluxed Iron Ore Pellets

Chen

Guo

et al. 2022

Metals

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The application of fluxed pellets in iron making industry has attracted considerable attention because of the better metallurgical properties than acid pellets and environmental friendliness compared to sinters. However, fluxed pellets with different binary basicity (CaO/SiO2) exhibited significant differences in phase composition, microstructure and consolidation mechanism. These differences mainly stemmed from the influence of calcium-containing substances in fluxed pellets. Herein, the theoretical investigation discovered the calcium-containing substances from fluxed pellets, including calcium iron silicate, calcium silicate and complex calcium ferrite (SFCA), which determined the properties of fluxed pellets. Microstructure analysis revealed that the calcium-containing substances filled between hematite particles were used as a binding phase to assist in pellets’ consolidation. Furthermore, the calcium-containing binding phase formed in the low-basicity (0.4–1.0) pellets was mainly composed of the calcium iron silicate glassy phase, while the binding phase of the high-basicity (1.0–1.2) pellets was dominated by SFCA belonging to SiO2-Fe2O3-CaO-Al2O3 multivariate system. In comparison, SFCA exhibited better crystallinity and reducibility than calcium iron silicate. Within the roasting temperature range of 1200–1250 °C, the increase of basicity contributed to the fluxed pellets obtaining better strength. To sum up, fluxed pellets with SFCA as the main calcium-containing binding phase can be obtained by increasing the basicity above 1.0–1.2, which was imperative for further improving the physical and metallurgical properties of fluxed pellets.

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Effect of fluxing agents on the swelling behavior of hematite pellets

Cited by 38 publications

References 10 publications

Effect of MgO addition on the metallurgical properties of the vanadium-titanium pellet with simulating blast furnace conditions

Effect of MgO addition on the metallurgical properties of the vanadium-titanium pellet with simulating blast furnace conditions

Effect of adding limestone on the metallurgical properties of iron ore pellets

Influence of Basicity and Calcium-Containing Substances on the Consolidation Mechanism of Fluxed Iron Ore Pellets

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