7TH EUROPEAN COKE AND IRONMAKING CONGRESS - ECIC 2016

Lithium silicate(Li4SiO4) was prepared by solid state reaction using leached residue(LR) from blast furnace slag as silicon source, and pure silica was chosen for comparison. Chemical analysis, scanning electron microscope(SEM) and X-ray diffraction(XRD) were used to characterize the Li4SiO4 prepared in the present study. Thermogravimetric analysis was carried out to obtained the absorbed curves for Li4SiO4 with different silicon source. The results indicated that silicon in blast furnace slag can be used as silicon source to prepare Li4SiO4, and silica in leached residue of blast furnace slag is indeed all amorphous. The Li4SiO4 prepared by LR showed dense polygonal particles with particle size between 16 and 47μm. however, the Li4SiO4 prepared by pure silicon showed dense polyhedral particles with particle size between 55 and 90μm, and formed agglomerates. The initial absorbed temperature and final absorbed temperature are 760.62K and 982.94K, respectively. Coats-Redfern method was used to calculated the kinetic parameters in absorption process, and the activation energy for absorption process of PS-Li4SiO4 and LR-Li4SiO4 are 146.11kJ/mol and 99.61kJ/mol, respectively.