| Summary: | 碩士 === 國立臺北科技大學 === 資源工程研究所 === 99 === The aim of this study was to utilize water treatment sludge and coal fly ash to prepare water treatment sludge geopolymer. The effects of content of water treatment sludge, particle size of sludge, calcined temperature and calcined time of sludge to compressive strength, physical properties, thermal conductivity and micro-structure of geopolymer would be investigated and silicate and aluminate dissolving test of water treatment sludge would be evaluated. The results indicated that the compressive strength of geopolymer prepared by water treatment sludge calcination at 950℃ and lasting 6 hours cured after 28 days was 28.5MPa . It would be better and fit the standard of Portland cement. The spectra of 29Si and 27Al NMR implied that there were amorphous aluminosilicate gels coexisting in geopolymer. The XRD patterns showed that the amount of crystallinity present was mainly caused by SiO2, (Mg,Al)6(Si,Al)4O10(OH)8, Fe2O3 and CaCO3 phases present in geopolymer. The spectra of FTIR indicated that the vibrational band at 983～994 cm-1 was attributed to the Si-O-T (T=Si or Al) asymmetric stretching mode. Besides, the framework structure of Serpentine Chlorite and Illite in water treatment sludge was destroyed after calcination resulting in silicate and aluminate ions easily dissolved in alkaline solution ,leading to improved geopolymerisation. The microstructures of geopolymer showed that the appearance of geopolymer was compact.
Furthermore, The silicate and aluminate leaching test of water treatment sludge was conducted to evaluate the soluable Si/Al ratio of water treatment sludge with geopolymer .The results showed that calcined water treatment sludge would improved the leaching concentration of silicate, however, as calcination at higher temperature (950℃), and the spinel phase was formed leading to retarding the release of alumiate monomers. The Soluabe Si/Al ratio of geopolymer prepared by water treatment sludge calcination at 950℃ and lasting 6 hours was 2.36, higher than geopolymer prepared by coal fly ash (2.25), as well as fully geopolymerization and form well-structrue three dimension amorphous aluminosilicate, therefore having good properties.
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