Compressibility and Foaming behavior of steel slag/waste glass compositesby particle size distribution and foam agents

In present research, the foam glass-ceramic composites fabricated by window glass, steel slag and SiC, CaCO3 foaming agents were investigated by press–sintering method. The optimum sintering temperature was obtained at 1200°C with a 3-minutes holding time and 20°C/min heating rate. The optimum pressure level of 80 MPa for achieving the 70 % of relative density was selected. The effect of particle size distribution of starting materials on the green and fired density of resulted glass-ceramics composites was evaluated. The composite's green density was 1.7g/cm3 obtained using the following particle size (49 wt. % 150μm, 21wt. % 85μm, 21wt. % 65μm, 9wt. % 45μm). It was shown that using medium-fine grade of the slag powder, the compaction and green densities of samples were increased up to 16% while in the case of slag/glass composites (due to the high hardness of the glass powder), the compaction of composite was  increased 11% compared to the coarse grade particles bearing samples. It was observed that finer particle sizes (below 75 μm) significantly cause more foaming and lower density (about 80 wt.% porosity). This can be due to the faster coalescence process and gases trapping which was arisen from the decomposition of foam agent.