Study On Preparation Of Foam Glass Using Zeolite As Pore Former

Foam glass has been prepared using the waste glass powder as basematerial, introducing zeolite as the pore former innovatively and adding fluxand foam stabilizer. The composition and melting characteristics of basematerial waste glass, composition and structure of pore former zeolit, and theeffects of the type and dosage of flux and foam stabilizer on themicrostructure, bending strength, total porosity, apparent porosity, waterabsorption rate and other performance indexes of foam glass have beeninvestigated systematically by means of testing techniques such as DTA-TG,XRD, FE-SEM, XRF, high temperature microscope, universal testing machineand thermal conductivity test instrument. The thermal conductivity andcorrosion properties of foam glass prepared under the optimizing processconditions have also been researched.The results show that the optimizing process parameters of foam glasspreparation using zeolite as single pore former are that the optimum ratio ofzeolite to waste glass is2:8, the addition amounts of optimal flux borax andfoam stabilizer trisodium phosphate are6wt%and4wt%, respectively, theoptimal heat treatment temperature is810℃, the holding time is35min, theheating rate is12℃/min. The volume density, flexural strength, totalporosity, water absorption and the thermal conductivity of foam glass with theoptimal comprehensive performances combined with microstructure are889Kg·m^-3,6.57Mpa,68.7%,6.7%,7.55%and0.105W/m·k, respectively, thesulfuric acid corrosion resistance performance of this sample is also veryexcellent.On the basis of above study, complex pore former and modifiers havebeen introduced in order to further improve the porosity and comprehensiveperformances, the effects of types and addition amounts of complex poreformer on the structure and performances of foam glass have been studied, thethermal conductivity and the acid corrosion resistance performance of foamglass with the optimal comprehensive performances combined with optimummicrostructure have also been tested.It is discovered that all the pore former composite system of zeolite+bamboo charcoal powder, zeolite+sodium carbonate, zeolite+calciumcarbonate, zeolite+bamboo charcoal powder+sodium carbonate, zeolite+bamboo charcoal powder+calcium carbonate, zeolite+sodium carbonate+ carbonate zeolite+bamboo charcoal powder+sodium carbonate+calciumcarbonate can reduce the bulk density of foam glass, increase its porosity.On the basis of the sample with the lowest bulk density prepared usingthe complex pore former of zeolite+sodium carbonate+calcium carbonate,modifier SiO₂with the optimizing dosage of1wt%has been introduced, thevolume density, flexural strength, total porosity water absorption and thethermal conductivity of foam glass are650Kg·m^-3,2.96Mpa,77.2%,7.1%,10.92%and0.083W/m·k, respectively. The volume density, flexural strength,total porosity water absorption and the thermal conductivity of foam glassprepared using MgO as modifier with the optimizing dosage of3wt%are711Kg·m^-3，5.12Mpa,75%,3.3%,4.64%and0.085W/m·k respectively. Whenusing CaO with the optimal dosage of1wt%as modifier, the volume density,flexural strength, total porosity water absorption and the thermal conductivityof the sample are601Kg·m^-3,2.15Mpa,78.9%,8.0%,10.08%and0.076W/m·k, respectively. The acid corrosion resistance performances of thesample prepared using the optimizing modifier MgO confirmed bymicrostructure and comprehensive properties is excellent. The flexuralstrength of foam glass prepared using zeolite as the pore former is3⁷timeshigher than that of samples with roughly the same density prepared usingtraditional pore former.