Production of glass-ceramics from MSW-fly ash and Dexing copper mine-tailing: Crystallization kinetics, structure, properties and immobilization of heavy metals
Jianlei Liu, Huiling Peng, Hua‐Nan Peng, Jie Zheng, Zhou Zhang, Hongde Ye, Hongqiang Wang, Zhumei Yu, Xianhong Zhu, Qikun Wang
Abstract
To reduce the environmental pollution from MSW-fly ash and Dexing copper mine-tailing and realize their maximum utilization, this research used them to synthesize novel eco-friendly glass-ceramics. Effects of different nucleation-crystallization temperatures on the crystal evolution, microstructure, properties, leaching behavior of heavy metals were discussed. The findings indicate that the crystallization activation energy E is 381 kJ/mol, and the crystallization mechanism is two-dimensional crystallization controlled by diffusion with an increasing nucleation rate. The difference in the nucleation-crystallization temperature will affect the precipitation and growth of crystal (CaAl 2 Si 2 O 8 ) in this glassy system, and further affect the microstructure and properties of the prepared glass-ceramics. Furthermore, because the glass-ceramics is the combination of glass and crystal, an obvious immobilization effect for heavy metals Fe, Mn and Cr can be obtained in our glass-ceramics. Apart from the high immobilization efficiencies for heavy metals, our glass-ceramics also show low density (2.715–2.761 g/cm 3 ) and water absorption (0.026–0.045%), high Vickers hardness (5.72–6.39 GPa), good chemical stability ( k H2SO4 : 3.68–28.72%, k NaOH : 0.01–0.96%), which confirms the potential and feasibility of the MSW-fly ash-Dexing copper mine-tailing-derived glass-ceramics as building decoration material.