Research On Alumino-silicate Fiber And Structure And Property Of Alumino-silicate Fiber Paper

The character of alumino-silicate fibers was analyzed. The results showed that:shot content of alumino-silicate fibers is up to35.91%, which is the reason why rawmaterials must be pretreatment brfore making refractory paper; The amount of waterabsorption is only0.044%in the condition of room temperature25oC and relativehumidity65%; Zeta potential of alumino-silicate fibers is-26.60mV; SEM imagesshow that alumino-silicate fibers were cylindrical and have very smooth surface;Alumino-silicate fibers have good resistance for chemicals, especialy for acidsolutions; FTIR spectra of alumino-silicate fiber indicated that, the symmetricstretching vibration absorption peak of Si-O-Si were poorly split, speculating that thefiber contains more non-bridging oxygen bond and the presence of Al makes itselfgo into tetrahedron network replacing Si, and also there may be substitutions betweenFe and Si, Fe and Al.In order to improve the evenness of alumino-silicate fiber paper, the dispersionproperty of alumino-silicate fibers were studied deeply. The basic dispersionconditions were determined; To further improve the dispersibility of alumino-silicatefibers, the influence of fiber dispersants including water-soluble polymer (APAM,CMC and PEO), inorganic electrolyte (sodium hexametaphosphate), anionicsurfactants LAS, SDS on the dispersibility of alumino-silicate fibers were studied.The results show that fiber dispersants could improve the dispersion of thealuminuo-silicate fibers. Compared to sodium hexametaphosphate, water-solublepolymer were more effective, the optimum amount is from0.3to0.4%(on drypulp); SDS was an ideal dispersant for this kind of fibers, When the amount of SDSis8%, alumino-silicate fibers can disperse very well in water; Additionally,alumino-silicate fibers were modified using CS. The influence of reaction temperature,time and amount of CS on the sedimentation volume of alumino-silicate fibers wereinvestigated; The optimum condition was obtained by orthogonal experiments, whichis that reaction temperature, reaction time and CS dosage is40℃,40minand1%(dry pulp), respectively. By analysing the FTIR spectral, the results show that thenature of CS modification is physical coating.The effect of inorganic adhesives (water glass, aluminum sol, PAC) organicadhesives (CMC, PVA, CS), sepiolite fiber and PVA fiber on strength of alumino-silicate fiber paper were also studied. It was found that alumina sol hashigher bonding strength as well as better temperature resistance property. Theoptimum dosage of alumina sol was30%; At900oC, the loss amount of refractorypaper added alumina sol was only1.56%; The sheet structure were observed by SEM,showing that alumina sol existed on the surface of alumino-silicate fibers in thepunctate form, which was helpful to improve the flexibility of alumino-silicate fiberpaper; Compared to PVA, CS, CMC showed better performance. When addingamount of CMC is25%, the insulation paper having good operational strength andintensity of usage can achieved. To determine its using temperature range, theobtained maximum CMC can be used as good adhesive under300oC; The optimumsubstition amount of sepiolite fibers for alumino-silicate fibers was30%, when tensilestrength of insulation paper increased greatly; PVA fibers can significantly improvethe physical strength of alumino-silicate fiber paper, but the addition amount shouldbe strictly controlled. Otherwise, heating cylinder would be very sticky, which washarmful to normal production; The optimum amount is between3%and4%, when thetensile strength can be up to1.5N m/g; Comparing PVA fibers with PVA solution,the results show that PVA fiber was better than PVA solution, and can replace PVAsolution for the production of alumino-silicate fiber paper; What’more, sheet structurewere analyzed using SEM, respectively; Finally, the effect of fiber ratio on thestrength of the paper was studied and the optimum mass ratio of alumino-silicate fiberto PVA fiber to sepiolite fiber is90:4:6, when tensile strength of alumino-silicate fiberpaper is up to1.556N m/g.The effect of slag ball, bulk density, temperature, and adhesive on the refractoryproperty of alumino-silicate fiber paper were studied. The results showed that the shotwould seriously affect the quality of the refractory products as well as their insulationperformance. That is the reason why they must be removed before using; Whenchoosing alumino-silicate fiber, sepiolite fiber and PVA fiber as raw materials forproduction of alumino-silicate fiber paper, the optimum bulk density is300~320kg/m3; As temperature increases, the curve of thermal conductivity to temperatureis in the form of exponential growth; The lowest thermal conductivity can achievedwhen the amount of alumina sol is30%.