The Dexing copper tailing (DCT), Coal slag (CS) and Red mud (RM) were used to prepare a solid waste-derived glass-ceramics. The result shows that the stable base glass can be formed when DCT/CS/RM mass ration is 35/25/40. Different crystallization temperatures (780∼980 ℃) were implemented on the base glass, and found that the glass-ceramics with Ca(Mg0.5Al0.5)((Si1.5Al0.5)O6) as the main crystal phase can be synthesized, whose bulk density, water absorption, Vickers hardness, bending strength, acid/alkali-resistance are in the range of 2.747∼2.887 g/cm3, 0.010∼0.027 %, 6.65∼8.24 GPa, 33.89∼118.53 MPa, 67.77∼99.97/97.85∼99.98 %, respectively. Especially, the GC880 not only shows the best properties (bulk density: 2.87 g/cm3; water absorption: 0.018 %; Vickers hardness: 6.96 GPa; bending strength: 118.53 MPa; acid/alkali-resistance: 99.34/99.97 %), but also has an solidification effect on heavy metal ions (Cr3+/Mn2+/Fe3+/Cu2+/Ni2+), wherein the leaching concentration reduction rates of Mn2+ and Fe3+ are over 97 %, which has the potential to be applied in decorative glass-ceramics.
Read full abstract