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Journal of Thermal Analysis and Calorimetry

, Volume 139, Issue 2, pp 923–931 | Cite as

Investigation on the structure, fluoride vaporization and crystallization behavior of CaF2–CaO–Al2O3–(SiO2) slag for electroslag remelting

  • Yu Liu
  • Yong Wang
  • Guangqiang LiEmail author
  • Cheng Yuan
  • Ru Lu
  • Baokuan Li
Article

Abstract

The structure, vaporization behavior and crystallization of CaF2–CaO–Al2O3 slags with different SiO2 contents for electroslag remelting were investigated by employing the TG and DSC measurements in conjunction with the Raman spectroscopy measurement for linking the macroscopic physicochemical property and microstructure information. The results show that SiO2 addition makes the depolymerized aluminate units polymerized into fully polymerized QAl4 unit and Al–O–Al complex structural groups. With the SiO2 content increasing to 6.1 mass%, the vaporization rate of fluoride increases because the SiF4 possessing higher vapor pressure is formed and the SiO2 addition can promote the formation of AlF3. As SiO2 content is further increased to 8.6 mass%, the vaporization rate of fluoride decreases because the mass transfer becomes slower. The more complex slag structure resulted from SiO2 addition dramatically decreases the crystallization temperature of the primary crystalline phase and the size of crystalline particles in the solidified slag.

Keywords

SiO2 addition Slag structure Vaporization Crystallization Electroslag remelting 

Notes

Acknowledgements

The authors gratefully acknowledge the support from the Key Program of Joint Funds of the National Natural Science Foundation of China and the Government of Liaoning Province (Grant No. U1508214) and the National Natural Science Foundation of China (Grant No. 51210007).

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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2019

Authors and Affiliations

  • Yu Liu
    • 1
    • 2
  • Yong Wang
    • 2
  • Guangqiang Li
    • 1
    • 2
    • 3
    Email author
  • Cheng Yuan
    • 2
  • Ru Lu
    • 2
  • Baokuan Li
    • 4
  1. 1.The State Key Laboratory of Refractories and MetallurgyWuhan University of Science and TechnologyWuhanChina
  2. 2.Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of EducationWuhan University of Science and TechnologyWuhanChina
  3. 3.Collaborative Innovation Center of Steel TechnologyUniversity of Science and Technology BeijingBeijingChina
  4. 4.School of MetallurgyNortheastern UniversityShenyangChina

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