Effect of Slag Chemistry on the Desulfurization Kinetics in Secondary Refining Processes

Kang, Jin Gyu; Shin, Jae Hong; Chung, Yoonsun; Park, Joo Hyun

doi:10.1007/s11663-017-0948-2

Cited by 29 publications

(22 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This indicates that F − can easily replace the position of O 2 − , and an O 2 − ion tends to replace two F − ions to maintain local electrical neutrality. 17,18) As a result, F − can break the TTM network and reduce the stability of the lattice structure, thus accelerating the reduction process. Therefore, the induced structural changes facilitated the reduction of the TTM, and also can decrease the melting point, which will be beneficial to the growth of metallic iron grains.…”

Section: Effect Of Caf 2 Dosagementioning

confidence: 99%

Extraction of Iron from Refractory Titanomagnetite by Reduction Roasting and Magnetic Separation

2021

View full text Add to dashboard Cite

The abundant refractory titanomagnetite (TTM) provides a cheap alternative source of iron, but this ore contains impurities and is difficult to process to make suitable concentrates for the blast furnace. In this study, reduction roasting of a primary TTM concentrate followed by magnetic separation was investigated to understand the effects of reduction time, coal dosage, and CaF 2 addition on the reduction behavior of TTM and growth mechanism of iron particles. The phase composition of reduced samples was characterized by X-ray diffraction. The size distribution of iron particles was quantitatively examined using image analysis. Results showed that CaF 2 can help improve the reduction degree and particle size of metallic iron. The metallization degree increased from 85.5% to 89.5% when the CaF 2 dosage increased from 0% to 4%, while a minor increase was observed when the CaF 2 dosage exceeded 4%. Accordingly, the TTM samples were treated by reduction roasting with 4% CaF 2 and 25% coal at 1 200°C for 60 min followed by magnetic separation. A magnetic concentrate with an iron content of 91.1% and a recovery of 92.9% was achieved. In addition, the relationship between the size distributions of iron particles and grinding fineness was also studied. The size distribution using data from the diameter of iron particles was found to be close to the actual grinding fineness.

show abstract

Section: Effect Of Caf 2 Dosagementioning

confidence: 99%

Extraction of Iron from Refractory Titanomagnetite by Reduction Roasting and Magnetic Separation

2021

View full text Add to dashboard Cite

show abstract

“…The chemical composition of refining slag has significant effect on steel cleanliness. Extensive studies have shown that highly basic refining slag favors deoxidation, 7) desulfurization 8) as well as the transformation of irregular Al 2 O 3 inclusions to globular CaO-MgO-Al 2 O 3 inclusions. 7,9) Yoon et al 10) reported that control of the %CaO/%Al 2 O 3 ratio at 1.7-1.8 in highly basic refining slag is the most effective way to remove Al 2 O 3 inclusions from bearing steel as the refining slag has low melting temperature and good fluidity.…”

Section: Introductionmentioning

confidence: 99%

“…A low slag viscosity enhances mass transfer in the slag phase, thus promoting the adsorption of non-metallic inclusions 13,14) and desulfurization. 8,15) Therefore, effect of CaF 2 content on the viscosity of some metallurgical slags has been extensively investigated. Wu et al 16) found that addition of less than 5% CaF 2 effectively decreases the viscosity of highly basic CaO-Al 2 O 3 -SiO 2 -MgO (C/S = 1.95-8.0) slags containing 25% Al 2 O 3 especially at low temperatures.…”

Section: Introductionmentioning

confidence: 99%

Effect of CaF2 on Viscosity and Refining Ability of Highly Basic Slags for Duplex Stainless Steel

Zheng

Wang

et al. 2021

ISIJ Int.

View full text Add to dashboard Cite

To optimize CaF 2 content in highly basic CaO-18%Al 2 O 3-SiO 2-10%MgO-CaF 2 (%CaO/%SiO 2 = 6, denoted as C/S = 6) refining slags used for the production of Al-killed duplex stainless steel with high cleanliness demand, the effect of CaF 2 content on the viscosity and refining ability of the slags were studied and compared with typical CaF 2-free highly basic CaO-30%Al 2 O 3-SiO 2-10%MgO (C/S = 6) slag. The effect of CaF 2 addition in decreasing slag viscosity becomes less obvious with increasing temperature and CaF 2 content. When CaF 2 content exceeds 10%, slag viscosity only marginally decreases with further increasing CaF 2 content. Both monoxide-CaO and monoxide-MgO phases are precipitated in all the CaF 2-bearing slags. CaF 2 addition slightly increases monoxide-MgO precipitation, but dramatically decreases monoxide-CaO precipitation. Viscosities of the CaF 2-bearing slags were also theoretically calculated and good agreement with the measured values was observed. Moreover, the 6% CaF 2-bearing slag has very close viscosities above 1 833 K but much lower viscosities below 1 833 K, compared with the CaF 2-free highly basic slag. Further evaluation of the 6% CaF 2-bearing slag on steel cleanliness confirms that 6% CaF 2 addition is sufficient for the highly basic CaO-18%Al 2 O 3-SiO 2-10%MgO-CaF 2 (C/S = 6) slag. The mechanism of CaF 2 in decreasing the viscosity of CaF 2-bearing slags was discussed from the viewpoints that CaF 2 behaves as a network breaker and that CaF 2 suppresses the precipitation of solid phases. The first aspect was identified to play a much greater role in decreasing slag viscosity.

show abstract

“…28,29) During Al-killed Ti-stabilized stainless steel refining process, high basicity (CaO/SiO 2 ) was commonly used for deoxidation, desulfurization, and inclusion-removing. 24,[30][31][32] However, high basicity slag usually has a high melting temperature and poor fluidity. CaF 2 was generally added to optimize the properties of high basicity slag.…”

Section: Effect Of Cao-mgo-sio 2 -Al 2 O 3 -Tio 2 Slags With Differenmentioning

confidence: 99%

Effect of CaO–MgO–SiO2–Al2O3–TiO2 Slags with Different CaF2 Contents on Inclusions in Ti-Stabilized 20Cr Stainless Steel

Cheng

2019

ISIJ Int.

View full text Add to dashboard Cite

Effect of Slag Chemistry on the Desulfurization Kinetics in Secondary Refining Processes

Cited by 29 publications

References 41 publications

Extraction of Iron from Refractory Titanomagnetite by Reduction Roasting and Magnetic Separation

Extraction of Iron from Refractory Titanomagnetite by Reduction Roasting and Magnetic Separation

Effect of CaF<sub>2</sub> on Viscosity and Refining Ability of Highly Basic Slags for Duplex Stainless Steel

Effect of CaO–MgO–SiO<sub>2</sub>–Al<sub>2</sub>O<sub>3</sub>–TiO<sub>2</sub> Slags with Different CaF<sub>2</sub> Contents on Inclusions in Ti-Stabilized 20Cr Stainless Steel

Contact Info

Product

Resources

About