Regular Article

Effective mechanism of BaO on the structure and fluid behavior of CaO-SiO₂-B₂O₃-based melts

¹ School of Metallurgical Engineering, Anhui University of Technology, Anhui, Ma’anshan 243032, China
² Key Laboratory of Metallurgical Emission Reduction & Resource Recycling (Ministry of Education), Anhui University of Technology, Anhui, Ma’anshan 243002, China

^* e-mail: wuting@ahut.edu.cn

Received: 20 June 2021
Accepted: 14 February 2022

Abstract

The influence of BaO contents on structure and fluid behavior of fluorine-free CaO-SiO₂-B₂O₃ based melts were examined using molecular dynamic (MD) simulation, rotary viscometer, X-ray diffraction and Fourier transform infrared spectroscopy. The FTIR results matched well with the MD simulation results that with the addition of BaO contents in CaO-SiO₂-B₂O₃ based melts, more cations were provided to balance the negative charge of [BO₄]^5– tetrahedrons, leading to the structures of Si-O and B-O were more aggregated and the adjacent structural units were more closely connected, which made the structure complex, so the viscosity of mold fluxes at high temperature in the basicity range 1.15–1.25 was intensify. Meanwhile, when BaO replaced CaO under distinctive basic conditions, the viscous activity of fluorine-free mold flux was decreasing generally, showing that as the temperature was decreased, the tendency of slag to converge into complex network structural units was also decreasing, which states the improvement of lubrication capacity of the slag during cooling process.