Effect of B2O3 content on viscosity and structure of SiO2-MgO-FeO-based slag
(School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China)
Abstract: The effect of B2O3 content on the viscosity of SiO2-MgO-FeO-based molten slag system was investigated using the rotating cylinder method. The evolution process of the melt structure under different contents of B2O3 was comprehensively studied via FTIR spectroscopy and a model for calculating the degree of polymerization was developed. The results showed that the viscosity of the molten slag decreased with the addition of B2O3, which had a slight effect when its content exceeded 3 wt.%. As the addition of B2O3 increased from 0 to 4 wt.%, the break temperature of the slags decreased from 1152 to 1050 °C and the apparent activation energy decreased from 157.90 to 141.84 kJ/mol. The addition of B2O3 to the molten slag destroyed the chain silicate structure to form a more cyclic borosilicate structure. The Urbain model was improved to calculate the viscosity of the SiO2-MgO-FeO-based slags, and the values were in good agreement with the experimentally measured values.
Key words: B2O3 content; molten slag; viscosity; activation energy; structure