| 摘要: | 本研究利用國內北部兩不同處理流程之下水污泥焚化灰渣，改變其熱處理之溫度(1050℃-1150℃)、時間(10min-30min)，及主成份(SiO2、Al2O3及Flux)比率進行燒結實驗，以探討其燒結特性、產生輕質化之機制，與適當之燒結控制條件。實驗中並藉SEM、XRD等分析技術，以了解試體微結構及晶相物之種變化。 實驗污泥灰中各主要重金屬(Pb、Cd、Cr、Cu、Zn)總量極低，其TCLP溶出濃度亦皆低於管制標準。實驗結果顯示，下水污泥灰之適當發泡溫度範圍約在1060－1090℃之間，主要受主成份特性之影響，經適當燒結溫度與時間之控制，所產生骨材可符合 CNS 常重骨材或輕質骨材之規範，輕質骨材密度可達低於1.6g/cm3之範圍。 在污泥灰調質實驗方面，以廢玻璃粉進調質，可增加其SiO2含量，降低玻璃相產生之熔點，促進玻璃相之形成，進而降低輕質化之溫度；而添加Al2O3則減緩發泡時間，但亦會增強試體之抗壓強度；另外添加少量垃圾焚化飛灰(5%)，亦可降低發泡之溫度，但隨添加量增加，反而造成發泡溫度緩慢上升，顯示其雜質(Flux)中之物種對其發泡現象產生交互影響。 This study investigated the sintering characteristics of sewage sludge incinerator ash (SSIA) for porous lightweight aggregates, by heating the SSIA (from two different-processed sewage plants) under controlled conditions of varifying temperature (1050-1150℃), time (10-30 min.), and sludge ash components (SiO2, Al2O3, and flux). SEM and XRD techniques were used to examine the thermal treatment properties, including the bloating mechanism, microstructure, and speciation variation. The tested raw SSIA has considerably low contents and TCLP leaching concentrations for Pb, Zn, Cu, and Cr, all meeting the regulatory thresholds. The results indicate that the SSIA bloated well within 1060-1090℃, mainly characterized by its components, heating temperature and time. Properly controlled conditions could produce aggregates that meet CNS for common and lightweight standards. A lightweight density as low as 1.6 g/cm3 can be obtained. With respect to the modification of SSIA compositions, it was found that the addition of cullet increased the SiO2 content, lowering the melting point, and further the bloating temperature of the ISSA. On the other hand, the addition of Al2O3 delayed the bloating time but strengthened the compressive strength of the resultant aggregates. Moreover, the addition of small amount (5%) of MSW incinerator fly ash could lower the bloating temperature, whereas excess amount resulted in a slow but increasing bloating temperature, suggesting the interaction between the flux species in the ISSA. |
