Ingredient manipulations of raw materials were always an important issue in the field of recycling silicate solid wastes of mining and metallurgy processes. For this purpose, glass-ceramics of CaO-MgO-Al2O3-SiO2 quaternary system were successfully produced by the method of melting, using Baiyunebo east mine tailing and fly ash as main sources of raw materials. The effect of carbon powder variation on the crystallization, and properties of the glass-ceramics were systematically investigated by differential thermal analysis (DTA), X-ray diffraction (XRD), Raman microscopy, scanning electron microscope (SEM) and mechanical testing. The results showed though carbon powder addition cannot change the formation of main crystal phase (augite), the concentration of this primary crystalline phase can be enhanced with the increase of the carbon powder addition to 5.6 wt%. As a result, the density, bending strength, acid-resistance and activation energy of the materials can be manipulated accordingly. And the mechanism of our manipulating process was close related to the reduction effect of carbon powder on decreasing the valence and concentration of iron ion within the studied glass ceramics.

Keywords: Glass ceramics; Baiyunebo east mine tailing; Iron; Augite; Carbon powder