| In recent years,with the continuous improvement of mining technology and mineral processing technology,the content of fine particles in mine tailings gradually increases,which brings new problems to the treatment of mine tailings.The particle size of superfine tailings is small,so it can’t be directly used as sand aggregate for goaf filling.However,as raw material of foamed ceramics,it can save grinding cost,and the preparation of green environmental protection inorganic thermal insulation material is an important part of national development of building energy conservation.In this paper,ultra-fine gold tailing is used as the main raw material to prepare foamed ceramic thermal insulation materials with light weight,high strength and high temperature resistance by powder sintering method at low temperature.The utilization of ultra-fine gold tailing reaches 80%.In this paper,combined with the advantages of chemical foaming method and hollow bead method,fly ash hollow bead was introduced into chemical foaming method to improve the original foaming method and form a new foaming system,so as to reduce the sintering temperature The properties and structure of the foamed ceramic insulation materials were analyzed and characterized by strength test.The effects of different factors on the internal bubble shape,distribution characteristics,external mechanical properties,thermal conductivity and apparent density of the samples were revealed.The main research work is as follows1.The advantages and disadvantages of two common preparation methods of foamed ceramics are analyzed.Aiming at the problem of high sintering temperature of foamed ceramics,combined with the advantages of both methods,a practical and effective preparation method to reduce the sintering temperature is proposed,and its cooling principle is studied.2.The effects of different proportions of ultrafine gold tailings and fly ash hollow microspheres on the properties of foamed ceramics were studied.Through the combination of single factor test and orthogonal test,the optimum dosage of additive was determined.Firstly,the effect of additives on the performance of foamed ceramics was analyzed by single factor test.Then L9(34)orthogonal test was designed.Taking silicon carbide,sodium fluorosilicate and talc as factors,the apparent density,compressive strength and thermal conductivity of samples as evaluation indexes,and finally the best additive formula was optimized,And explore the significant relationship of additives on the properties of foamed ceramics.3.The problems encountered in the previous experiments were analyzed,and the properties of the foamed ceramics were optimized by optimizing the grinding process and sintering process.Through the single factor test of grinding mode,grinding time and grinding additive content,the best grinding process was determined by taking viscosity as the evaluation standard.Through the single factor test of preheating temperature,foaming temperature,holding time and heating rate,taking the apparent density,compressive strength and thermal conductivity as the indexes,the influence of sintering process on the properties and microstructure of foamed ceramics was analyzed,and the best sintering process was determined.4.Through the macro and micro analysis of the foaming process and the analysis of the influencing factors of the foaming process,the foaming mechanism and new foaming system of the foamed ceramics with fly ash hollow beads were explored,and the differences between the foaming mechanism and chemical foaming method were analyzed.5.Through the economic comparison of different preparation methods,the cost advantage of the preparation method proposed in this paper is demonstrated,and a brief industrial design is carried out. |
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