Effect of BaO and Na2O on the viscosity and structure of blast furnace slag

• Published in: Ironmaking & steelmaking Vol. 47; no. 2; pp. 168 - 172
• Main Authors: Xu, Ren Ze, Zhang, Jian Liang, Han, Wang Xue, Chang, Zhi Yu, Jiao, Ke Xin
• Format: Journal Article
• Language: English
• Published: London, England Taylor & Francis 07.02.2020; SAGE Publications
• Subjects: BaO; Blast furnace slag; structure; viscosity; BaO; viscosity; Na2O; Blast furnace slag; structure
• ISSN: 0301-9233; 1743-2812
• DOI: 10.1080/03019233.2018.1498761

The effects of BaO and Na 2 O on the viscosity and structure of CaO-SiO 2 -MgO-Al 2 O 3 -based blast furnace slag were investigated using the rotating cylinder method and Raman spectra technique in this work. The results indicated that the slag viscosity first increased and then decreased with the addition of BaO and decreased with the increasing content of Na 2 O. When adding BaO into CaO-SiO 2 -MgO-Al 2 O 3 slag, Ba 2+ ion could compensate Al 3+ ion and form more complex aluminate or aluminate-silicate structures, which increased the degree of polymerisation and the viscosity of the slag. With the further addition of BaO, the content of SiO 2 decreased and the relative content of O 2− ion increased, which may slightly depolymerise the slag structure then decreased the viscosity. When adding Na 2 O into CaO-SiO 2 -MgO-Al 2 O 3 -BaO slag, Na 2 O may act as network modifiers which could simplify the complex silicate structures and lower the polymerisation degree of slags, therefore decreased the viscosity.