Preparation and properties of glass–ceramics derived from blast-furnace slag by a ceramic-sintering process

Glass–ceramics were synthesized using ground blast-furnace slag and potash feldspar additives by a conventional ceramic-sintering route. The results show 5 wt% potash feldspar can enhance the sintering properties of blast-furnace slag glass and the results glass–ceramics have desirable mechanical properties. The main crystalline phase of the obtained glass–ceramic is gehlenite (2CaO·Al2O3·SiO2). A high microhardness of 5.2 GPa and a bending strength higher than 85 MPa as well as a water absorption lower than 0.14% were obtained.