Study On Preparation And Performance Of Closed Cell Foam Ceramic Glass From High Silicon Polymetallic Tailings

This topic selects a certain high-silicon polymetallic tailings,mixed with fly ash as the base material,and silicon carbide as the foaming agent to prepare closed-cell foam glass ceramics.Based on the excellent thermal insulation product performance of glass foam ceramics and the economic characteristics of low price and easy availability of tailings,the tailings are made into high-performance foam ceramic glass.The production of such products will effectively enhance the economic effect of the enterprise and improve the ecology.The environment has formed a benign industry with multiple benefits.It not only effectively achieved the tailings removal,but also increased the economic and technical benefits of the tailings through secondary processing,and achieved the industrial green and high-efficiency recycling effect of "no danger,harmless,secondary recycling".In this experiment,the chemical composition and process mineralogy of the tailings were analyzed.The results show that its main composition is a mixture of quartz and feldspar,and the feldspar is mainly potassium feldspar.The total silicon content in the tailings is more than 80%,which is a high-silicon tailing;the tailings TG-DSC analysis results It shows that when the forming temperature of the melt is above 800?-900?,a large amount of eutectic phase appears and the viscosity drops sharply.On this basis,55%tailings and 34% fly ash are used as the main raw materials,and 11% sodium carbonate and 8% silicon carbide are added as the formula for preparing foam glass ceramics.Under the conditions of the best process system and raw material ratio,excellent products with uniform pores and stable structure can be produced.Based on the method of controlling variables,the factors that affect the performance of foam glass ceramics are studied,and it is found that the compressive strength,density,and water absorption of the product will have different morphology and performance changes with various influencing factors.In the study of the mechanism of the foaming process,it is found that the main way of gas generation required for foaming is the high-temperature decomposition reaction of silicon carbide.The tailings rich in potassium feldspar,due to the strong fluxing effect of a large amount of potassium,make the foaming temperature of the melt reaction far lower than the production temperature in the traditional process.A large amount of residual unreacted or incompletely reacted mineral rocks in the melt will be used as "coarse aggregates" in the structure to effectively enhance the structural strength.The total radioactivity ratio of the tailings selected in this experiment is 8.53×103Bq/Kg,which has reached the range of Class C decoration materials and can be used as raw materials for exterior wall building materials.However,considering the current standardization and strictness of the radioactivity requirements of tailings and building materials in my country,the radioactive minerals in the tailings have been studied and found that the radioactive sources are thorium and uranium,which mainly occur in niobium calcite and brown pectinite.Because of the dilute and fine-grained characteristics of these two minerals,it is difficult to eliminate with the current technology.