Study On Perfprmance Regulation Of Glass-ceramics Prepared From Waste Incinerator Slag And Molybdenum Tailings

Waste incineration slag and molybdenum tailings,as bulk solid waste,have low comprehensive utilization rate and added value,therefore it is urgent to explore their resource treatment technology.In this work,from the perspective of utilizing solid waste and increasing the added value,using waste incineration slag and molybdenum tailings as the main raw materials,the diopside ferroan-based glass-ceramics were prepared by melting-water quenching-sintering method without adding other substances.The effects of raw material ratio and sintering temperature on the phase composition,microstructure and properties of glass-ceramics were studied,and the mechanism of synergistic preparation of waste incineration slag and molybdenum tailings was explored.In addition,the glass-ceramics prepared from waste incineration slag and molybdenum tailings were optimized by introducing ZrO₂.The research results can provide theoretical and technical supports for the harmless disposal and high value-added utilization of waste incineration slag and molybdenum tailings.The main contents are as follows:（1）Using waste incineration slag and molybdenum tailings as raw materials,the glass-ceramics with diopside ferroan as the main crystal phase and anorthite as the secondary crystal phase was successfully prepared without adding other substances.The optimal preparation parameters were:the mass ratio of molybdenum tailings and waste incinerator slag was 55:45,the sintering temperature of 1000℃,and holding time of 2 h.The comprehensive performance of glass-ceramics was the best,and the leaching toxicity of heavy metals met the national standard.Its flexural strength,Vickers hardness,bulk density and water absorption were 76.00 MPa,5.77 GPa,2.69 g/cm³ and 0.32%,respectively.Under the best process conditions,the content of diopside ferroan and anorthite phase increased.Meanwhile,the grain size became larger,the distribution was uniform,the structure was denser,which contributed to the improvement of comprehensive performance of glass-ceramics.（2）Using waste incineration slag and molybdenum tailings as raw materials to prepare glass-ceramics can produce synergistic effects,which are mainly reflected in:the waste incineration slag has the compositional characteristics of high calcium and low silicon,and the molybdenum tailings have the compositional characteristics of high silicon and low calcium.It can meet the composition ratio requirements of diopside ferroan,which is beneficial to the increase of glass-ceramic crystal content;Na₂O and K₂O of the waste as fluxes are conducive to the formation of basic glass liquid phase,which can promote the diffusion of substances and improve crystallization rate;Fe₂O₃ and Ti O₂ of the waste as nucleating agents can promote the formation of crystal nuclei,which is beneficial to glass phase separation and crystal growth.Diopside ferroan and anorthite are intertwined and evenly distributed to form an interlocking structure,which leads to the improvement of the comprehensive properties of the glass-ceramics.（3）The introduction of 5 wt.%ZrO₂ could further promote the formation of diopside ferroan and improve the comprehensive properties of glass-ceramics.The optimal process parameters were as follows:ZrO₂ incorporated into the basic glass as raw material,the sintering temperature of 1000℃,and holding time of 2 h.The flexural strength,Vickers hardness,bulk density and water absorption of glass-ceramics were 100.03 MPa,5.86 GPa,2.74 g/cm³,and 0.30%,respectively.The introduced ZrO₂ could effectively play the role of crystal nucleating agent,promote crystal development,and improve crystal uniformity.