Regular Article

Structure evolution of blast furnace slag with high Al₂O₃ Content and 5 mass% TiO₂ via molecular dynamics simulation and fourier transform infrared spectroscopy

School of Metallurgy Materials Engineering, Chongqing University of Science and Technology, 401331 Chongqing, PR China

^* email: qinyuelin710@163.com

Received: 23 March 2017
Accepted: 19 October 2017

Abstract

The structure of a quenched blast furnace slag containing 5 mass% TiO₂ was investigated via molecular dynamics simulation and Fourier transform infrared spectroscopy. The simulation and experimental results obtained revealed that the slag possesses a depolymerized network of [SiO₄] and [AlO₄] tetrahedra. At a fixed CaO/SiO₂ mass fraction of 1.17 and 12 mass% Al₂O₃, increasing the amount of MgO decreased the bridging oxygen fraction in the slag system, thus resulting in silicate depolymerization. At a fixed CaO/SiO₂ mass fraction of 1.17 and 8 mass% MgO, increasing Al₂O₃ content increased the bridging oxygen fraction because of the polymerization of aluminate structures. At a fixed 8 mass% MgO and 12 mass% Al₂O₃, increasing the CaO/SiO₂ mass fraction from 1.07 to 1.50 decreased the bridging oxygen fraction because of the depolymerization of silicate and aluminate structures. Analyzing the slag structure via FT-IR spectroscopy verified these behaviors.