Effect of Na2CO3 content on thermal properties of foam-glass ceramics prepared from smelting slag

A new type of foam-glass ceramics was synthesized, by the method of powder sintering (one-step), with smelting slag and porcelain powder as the main raw material. Besides, the influence of sodium carbonate content on the changing trend of glass structure at high temperature and crystal structure of foam-glass ceramics were explored by modern analytical techniques such as DSC, XRD, Tom-ac, and the influence of Na2CO3 content on the viscosity of glass liquid during sintering was studied by VFT inverse proportional formula. When Na2CO3 content was between 0% and 5%, as Na2CO3 content increased, the volume density of the porous glass-ceramic continued to decrease, its porosity continuously increased. The sample prepared by the experiment is composed of wollastonite CaSiO3 and salite CaMgSi2O6. The sample's compressive strength in amounts up to 13.06 MPa and the density is 0.731 g/cm3. The results show that the addition of Na2CO3 has a great effect on the softening point, sintering temperature interval, and volume expansion rate of the mixtures, but has little effect on the crystal phase of the samples.