| Abstrakt: |
Abstract: Different Al2O3/SiO2 glass-ceramics were prepared from blast furnace slag by sintering method. The structure and properties of glasses or glass-ceramics were investigated by DSC, XRD, SEM, FTIR, 27Al MAS NMR. The DSC results showed that with the increase of Al2O3/SiO2, the glass transition temperature (Tg) first decreased and then increased, reached the minimum when Al2O3/SiO2 was 0.34. The volume density, bending strength and microhardness of glass-ceramics also showed the same variation rule. Structural analysis showed that when the Al2O3/SiO2 increased from 0.19 to 0.34, Q2 gradually transformed into Q1 and Q3; when the Al2O3/SiO2 continued to increase from 0.34 to 0.39, Q1 and Q3 decreased while Q2 increased. The variation of [AlO4] and [AlO6] made the glass network structure the loosest when Al2O3/SiO2 was 0.34. Gehlenite was the main crystalline phase in glass-ceramics, and with the increase of Al2O3/SiO2, the precipitation of gehlenite increased, while the precipitation of diopside and hyalophane decreased. |
