Preparation And Research Of SiO₂Aerogel And Zeolite From Industrial Waste Residue

Silica aerogels are a kind of lightweight nanopomus materials with low density, highporosity, high surface area and low thermal conductivity characteristics, and having broadapplication prospects in many areas. Zeolites comprise a rich class of microporous crystallinealumino silicates which have been widely used in catalysts, adsorbents, ion exchange and newfunctional materials due to the large surface area, higher thermal stability properties.The aim of this dissertation is to synthesis two high added value porous materials NaP1zeolites and silica aerogels by industrial waste fly ash as raw materials, and adoptingindustrial waste silica powder to prepare silica aerogels. Its can achieve fly ash and silicapowder resources of the use requirements.Preparation of two new porous materials technology blended in a process line, zeoliteand NaP1prepared silica aerogels were coinstantaneous synthesized by industrial waste flyash as raw material. The influences of process conditions on the synthesis of zeolite werediscussed. The samples’ crystalline phase, microstructure and functional group of thesynthesized NaP1zeolites and silica aerogels were observed and analyzed by XRD, SEM andFTIR, and the adsorption of copper ions of the synthesized zeolites were investigated. Theresults indicated that using silica aerogels were prepared by fly ash Filtrate, its surface weresmooth and showed small silicon holes network structure, its specific surface aera are743m²·g^-1, pore volume are2.32mL·g^-1and average pore diameter9nm. the NaP1zeoliteswith high crystallinity could be obtained by hydrothermal reaction with sodium hydroxidesolution using fly ash residue with Si:Al molar ratio=3:1at90℃. The synthesized NaP1zeolites had good adsorption properties of copper ions, its initial adsorption rate was fast, theadsorption capacity could reach to52.8mg·g^-1at30minutes, then the adsroption rate sloweddown gradually and closed to the adsorption saturation at60minutes, the saturatedadsorptivity could achieve82.7mg·g^-1.Silica aerogels were prepared via ambient pressure drying by usinghexane/ethanol/trimethylchlorosilane mixed solution to modify the sol-gel derived SiO₂wetgel, which were obtained from the sodium silicate precursors synthesized with hydrothermal process by adopting the solid waste of silica powder as raw materials. The microstructure,morphology and properties of the aerogels were analyzed by SEM, FTIR and BET adsorptionand desorption methods. The results indicate that the obtained silica aerogels possesscontinuously porous structure, with the specific surface area and porosity of silica aerogelsbeing767～828m²·g^-1and91.5%～95.1%, respectively. The results of adsorption of machineoils indicate that silica aerogels have good adsorption properties and the highest saturatedadsorption oil ratio can achieve1105%.