Utilization of Air Quenched Steel Slag in Decorative Ceramics with Higher Mechanical Properties

摘要

Air quenched steel slag is much more difficult to utilize than other kinds of steel slag. 50% percent of air quenched steel slag was used to prepare brown decorative ceramics. Due to the broken (SiO_4)_n glass network, the optimum sintering temperature decreases with increasing Na_2O and MgO, respectively. The major crystalline phase of the samples is diopside (CaMgSi_2O_6) with minor anorthite phase (CaAl_2Si_2O_8). Due to remelted glass phase, the X-ray diffraction intensity of the samples decreases with increasing Na_2O, while the intensity increases with increasing MgO which is beneficial to crystallization of the samples. The bending strength of the samples decreases with increasing Na_2O (from 155.3+/-2.49 MPa to 143.1+/-2.01 MPa), while the strength increases with increasing MgO (from 147.4+/-3.44 MPa to 169.4+/-4.04 MPa). The Vickers hardness of the samples shows similar trends with the bending strength. The samples exhibit much better mechanical properties than marble, granite, tile and other similar ceramics reported, and present good chemical resistance. Therefore, The ceramics based on air quenched steel slag may have great potential for applications as building decorative materials, and it provides a promising way for the utilization of air quenched steel slag.