Effect of High Al2O3 Slag on the Blast Furnace Operations

Sunahara, Kohei; Nakano, Koji; Hoshi, Masahiko; Inada, Takanobu; Komatsu, Shusaku; Yamamoto, Tomokazu

doi:10.2355/isijinternational.48.420

Cited by 64 publications

(32 citation statements)

References 15 publications

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“…While, the high temperature properties of blast furnace slags play an important role on the softening and melting behavior of raw materials in blast furnace. 1,2) Many researchers have found that the chemical composition, such as CaO/SiO2, Al2O3 and MgO content, have great influence on the fluidity and viscosity of blast furnace slags. [3][4][5] On the other hand, researchers also found that the sinter of high basicity would interact with lump ores or pellets at high temperature, the softening and melting properties of lump ores or pellets would be improved by the high temperature interaction.…”

Section: Introductionmentioning

confidence: 99%

Influence of High Temperature Interaction between Sinter and Lump Ores on the Formation Behavior of Primary-slags in Blast Furnace

Liu

Huang

et al. 2014

ISIJ Int.

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The primary-slags formation behaviors of sinter, lump ores and integrated burdens were studied to explore the high temperature interaction between sinter and lump ores in blast furnace. The results showed that the softening and melting properties of lump ores, viscosity and fluidity index of primaryslags of lump ores would be improved by the high temperature interaction. Particularly, the high temperature interaction was influenced by the chemical composition and porosity of iron ore samples. The high temperature interaction between sinter and lump ore L-2 (a typical limonite lump ore from Australia) was much stronger. Though the high temperature properties of lump ore L-2 was much worse than lump ore L-1 (a typical hematite lump ore from South Africa), the high temperature properties of integrated burden B (consist of sinter and lump ore L-2) was not worse than that of integrated burden A (consist of sinter and lump ore L-1) due to the strong high temperature interaction. In addition, the suitable MgO/Al2O3 weight ratio was calculated based on the assumption that the only phases of slags were akermanite and gehlenite, which showed a decreasing tend with the increase of CaO/SiO2 weight ratio.

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Section: Introductionmentioning

confidence: 99%

Influence of High Temperature Interaction between Sinter and Lump Ores on the Formation Behavior of Primary-slags in Blast Furnace

Liu

Huang

et al. 2014

ISIJ Int.

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“…Various operation tests such as Shaft Cupola process, 10) high PCR injection, PC and powder ore simultaneous injection or high Al2O3 slag operation have been performed. [11][12][13][14] Another operating experimental blast furnace is located in Luleå owned by LKAB (Luossavaara-Kiirunavaara Aktiebolag), Swedish mining company, constructed in 1997. 15,16) Already 25 campaigns were successfully carried out until 2010 winter at the LKAB's experimental blast furnace supported by Swerea MEFOS.…”

Section: )mentioning

confidence: 99%

Operation Trial of Hydrogenous Gas Injection of COURSE50 Project at an Experimental Blast Furnace

Watakabe¹,

et al. 2013

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COURSE50 (CO2 ultimate reduction in steelmaking process by innovative technology for Cool Earth 50) carried out COG and reformed COG (RCOG) injection operation trials at LKAB's experimental blast furnace in Luleå in cooperation with LKAB and Swerea MEFOS. Operation trials were successfully carried out. Input of C in both COG and RCOG injection periods decreased comparing the base period, because of increase in H2 reduction instead of C direct reduction that is a huge endothermic reaction. However poor penetration depth of injected gas from shaft tuyere made furnace efficiency worse. Hot top gas injection increased temperature of top gas and upper part of the furnace. Efficiency of hot top gas injection was not clear as sinter degradation did not occur in the base period.KEY WORDS: COURSE50; experimental blast furnace; blast furnace; CO2 emission; H2; COG; reformed COG; injection; hot top gas; sinter degradation. PrefaceCOURSE50 (CO2 ultimate reduction in steelmaking process by innovative technology for Cool Earth 50) is a national project for development of technologies for environmentally harmonized steelmaking process to achieve drastic CO2 emissions reduction in steel industry. Main targets of COURSE50 project are development of technologies to reduce CO2 emissions from blast furnace and development of technologies to capture, separate and recover CO2 from blast furnace gas. CO2 reduction technology from blast furnace consists of research of control reactions for reducing iron ore with hydrogenous reducing agents such as coke oven gas (COG) or reformed COG (RCOG). RCOG is amplified its hydrogen content in COG by utilizing newly developed catalyst and unused waste heat. Also a technology to produce high strength and high reactivity coke for reduction with hydrogen is under development.RCOG will be injected to the blast furnace through tuyeres located at lower part of the shaft of blast furnace, and COG will be injected through blast tuyeres to utilize CH4 combustion.Amount of O2 enrichment to the hot blast air has to be increased when COG is injected to the blast tuyere to maintain the flame temperature constant to compensate for heat of decomposition of hydrocarbon. It results in decrease in upper part temperature and decreased upper part temperature prolongs the residence time for sinter where disintegration is promoted. In addition, H2 may promote sinter deterioration. To prohibit prolonged residence time for sinter at low temperature range, top gas is partly combusted is injected in the upper shaft for temperature control. We call it hot top gas injection in this article.Basic and remarkable results are conducted through various laboratory tests and mathematical model calculation in COURSE50 project.3,4) H2 in COG or RCOG is expected to react with ferrous material very fast and to replace C as reducing agent of blast furnace.However, reaction in the blast furnace is much complicated because it is dominated by burden and gas distribution

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“…Kim et al [4] obtained the result that the viscosity decreased with the increase of MgO content which destroyed much of the network structure. Sunahara et al [5] researched the high Al 2 O 3 concentration blast furnace slag and found that the permeability of dripping zone was improved with the decrease of binary basicity (CaO/SiO 2 ). The blast furnace operation needs reasonable compositions of the slag for the blast furnace working smoothly.…”

Section: Introductionmentioning

confidence: 99%

Effect of Al₂O₃, MgO, and CaO/SiO₂on Viscosity of High Alumina Blast Furnace Slag

Ren

Wang

et al. 2015

steel research int.

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The effects of Al 2 O 3 , MgO, and binary basicity on the viscosity of high alumina blast furnace slag are studied systematically at the temperatures of 1773 K and below using the orthogonal experimental design method. The results show that, at fixed binary basicity (CaO/SiO 2 ) between 1.1 and 1.2, higher Al 2 O 3 content increase the slag viscosity due to the polymerization of the aluminate structures. At fixed Al 2 O 3 content between 15 and 20%, increasing the CaO/SiO 2 from 1.1 to 1.2 lead to lower viscosity due to the depolymerization of the aluminate structures. At fixed MgO between 9 and 11%, both increasing Al 2 O 3 content and CaO/SiO 2 can make the melting temperature increase. In addition, the viscosity data of high alumina blast furnace slag was in accordance with the estimated values of viscosity by Riboud model. Understanding the mechanism of Al 2 O 3 , MgO, and binary basicity on the viscosity of blast furnace slag can provide a promising method for optimizing its viscosity value and improving the blast furnace operation.

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Effect of High Al2O3 Slag on the Blast Furnace Operations

Cited by 64 publications

References 15 publications

Influence of High Temperature Interaction between Sinter and Lump Ores on the Formation Behavior of Primary-slags in Blast Furnace

Influence of High Temperature Interaction between Sinter and Lump Ores on the Formation Behavior of Primary-slags in Blast Furnace

Operation Trial of Hydrogenous Gas Injection of COURSE50 Project at an Experimental Blast Furnace

Effect of Al₂O₃, MgO, and CaO/SiO₂on Viscosity of High Alumina Blast Furnace Slag

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Effect of High Al2O3 Slag on the Blast Furnace Operations

Cited by 64 publications

References 15 publications

Influence of High Temperature Interaction between Sinter and Lump Ores on the Formation Behavior of Primary-slags in Blast Furnace

Influence of High Temperature Interaction between Sinter and Lump Ores on the Formation Behavior of Primary-slags in Blast Furnace

Operation Trial of Hydrogenous Gas Injection of COURSE50 Project at an Experimental Blast Furnace

Effect of Al2O3, MgO, and CaO/SiO2on Viscosity of High Alumina Blast Furnace Slag

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Effect of Al₂O₃, MgO, and CaO/SiO₂on Viscosity of High Alumina Blast Furnace Slag