Preparation, crystallization kinetics and stabilization behavior of the heavy metal ions of all-solid waste-based glass-ceramics from steel slag and coal gangue

Abstract

In this work, all solid waste-based glass-ceramics with 55% steel slag and 45% coal gangue were prepared by the conventional melt-quenching and two-step heat treatment methods. The effect of the heat treatment on the crystallization, microstructure, physical properties and stabilization behavior of the heavy metal ions for the glass-ceramics was researched by DSC, XRD, SEM and ICP-OES. Augite was the dominant crystal phase with a crystallinity about 94%. With a heat treatment of 750°C/6 h+900°C/2h, the flexural strength (328 MPa) and Vickers hardness (9.59 GPa) of the prepared glass-ceramic reached the optimal. The immobilization efficiencies of the glass-ceramics for the heavy metal ions almost reached above 90%. The above results suggest that the use of all-solid waste for the preparation of glass-ceramics may be a feasible way to achieve the immobilization of heavy metal ions.