Preparation and mechanism of silicate-based sintering material from large amount of steel slag

In this paper, silicate-based sintering materials (SBSM) were prepared by high-temperature sintering process with steel slag as the main raw material. By strictly controlling the particle gradation of steel slag, the content of steel slag in SBSM was increased to 70%, to realize the efficient resource utilization of steel slag. The phase composition and micro-morphology of the SBSM were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The flexural and compressive strength of the SBSM were tested by the full-automatic compression and folding machine. The results show that the main phases of the SBSM are anorthite and quartz, and the existence of anorthite is benefit to improve the mechanical properties of the SBSM. An appropriate proportion of small-size steel slag (more than 100 mesh) can promote the reaction process, and improve the flexural and compression strength of the samples. However, excessive small-size particles of steel slag lead to a large amount of liquid phase in the reaction process, which makes the aggregate react with the matrix. The strength of the sample decreases with the decrease of its resistance to external forces. The water absorption of the samples decreases with the increase of the steel slag with small-size particles.