Characterization of glass-ceramics developed from zinc leaching residue by sintering method

Abstract

Zinc leaching residue is the waste residue produced by the wet zinc extraction process, which cannot be effectively utilized due to its complex composition and the presence of toxic heavy metals. At this stage, a large amount of residue is piled up in the tailing storage, there is a waste of resources and the risk of environmental pollution. This paper introduced a study on the preparation of glass-ceramic in building materials from zinc leaching residue by the sintering method, using silica sand and albite as additives. It was found that the glass-ceramics prepared with zinc leaching residue incorporation of 70–75 % and sintering temperature in the range of 900–1000 °C exhibited excellent mechanical properties and stable chemical properties. The zinc leaching residue content and the sintering temperature together controlled the crystallization process and influenced the properties of the glass-ceramic. Increasing the zinc leaching residue content caused an increase in the content of non-bridging oxygen bonds in the glass-ceramic, which led to an increase in the degree of polymerization of the matrix and a decrease in the activation energy of the crystallization, which promoted the crystallization process. Higher temperatures provided more energy for the crystal crystallization reaction and facilitated the process. The glass-ceramics showed good solidification of heavy metals and compliance with the requirements for various heavy metals in the toxicity leaching test. The glass-ceramic made from zinc leaching residue eliminated the risk of heavy metals contamination and was a green, harmless, high-performance material that can be used in a wide range of fields.