Production of glass-ceramics from metallurgical slags

The CaO-MgO-Al2O3-SiO2 (CMAS) glass-ceramics are a new type of building decoration materials. They can be prepared using silicate-bearing metallurgical slags as raw materials for both economic and environmental ben-efits. This study offered a systematic review of preparation of CMAS glass-ceramics from various metallurgical slags based on analyses of characteristics, preparation methods of slag-based glass-ceramics, and the influence of heat treatment, chemical components and nucleating agents on the phase composition, microstructure and properties of glass-ceramics. It was found that a large number of metallurgical slags, including blast furnace slag (BFS), steel slag (SS), stainless-steel slag (SSS), electric furnace ferronickel slag (EFFS), copper slag (CS), ferro-manganese slag (FS) and lead fuming slag (LFS), have the potential to serve as the main raw materials for producing CMAS glass-ceramics because of their chemical composition similarities to the products. However, the minor or residual elements, such as chromium, in the slags may directly affect the properties of the glass-ceramics mainly because of their impacts on the nucleation and crystallization in parent glasses which are in need of control. Special attention of this review was devoted to the challenges from the aspects of cost, safety and diversification in preparing the glass-ceramics from metallurgical slags and to corresponding solutions for maximizing utilization of the wastes with desirable product quality.

Automated summary

CMAS glass-ceramics, using metallurgical slags as raw materials, have potential for economic and environmental benefits. This study provided a systematic review of preparation methods, challenges, and solutions for utilizing metallurgical slags in producing CMAS glass-ceramics.