| Popis: |
Diatomite-based porous ceramics were prepared by hand compression molding under low temperature sintering, using diatomite as raw material, sodium carbonate and polyvinyl alcohol (PVA) as additives. The effects of sintering temperature, addition amount of sodium carbonate and PVA on the properties of porous ceramics were discussed. The prepared porous ceramics were characterized by mercury porosimeter, XRD, SEM and FTIR. And the adsorption of methyl orange by porous ceramics was investigated. The results show that the performances of porous ceramics, such as porosity and crushing strength, change with the addition amount of sodium carbonate and PVA, also the sintering temperature. The optimum formula for preparing porous ceramics used as carrier and filter simultaneously consists of 100 portions of calcined diatomite, 10 portions of sodium carbonate, 150 portions of water, PVA and polyacrylamide (PAM) solution[m(H2O):m(PVA):m(PAM)=1000:4:4]. When sintered at 900°C, the porosity, crushing strength, average pore diameter and specific surface area of prepared porous ceramics are 71.74%, 4.535MPa, 10.023μm and 230m2/g, respectively. The prepared porous ceramics are composed of tetragonal cristobalite. And the decoloration conversion for methyl orange of prepared porous ceramics can reach 40.43% in 90 min. |
