已往都市垃圾焚化底渣再利用的產品常為道路級配、管溝回填料、填方材等，而為了增加底渣回收再利用之價值，嘗試將底渣進行輕質骨材的燒製。早期輕質骨材皆以天然材料為素材，如浮石、膨脹頁岩、板岩、黏土礦物等，而都市垃圾焚化灰渣由於成份複雜，性質不均，和天然膨脹材料與其他人工膨脹材料的性質差異甚大，需經適當調整。 本實驗將SiO2和Fe2O3添加於研磨後之粗粒徑底渣，利用不同燒結條件觀察粒料受熱膨脹之情況，進一步設計膨脹氣體收集裝置，將燒製過程所產生之氣體進行分析。實驗共分成四個階段。實驗一：研究氧化鐵添加對膨脹氣體產生之影響；實驗二：研究添加SiO2之影響；實驗三：研究添加細底渣之變化；實驗四：進行不同燒結氣氛之研究。 由實驗結果得知，經逸氣分析系統進行膨脹氣體收集研究是可行的，也確認膨脹過程中CO2於高溫焙燒時產生。添加SiO2對產氣並無太大影響，而原料添加10％細底渣後，CO2的產生趨勢與實驗一和實驗二相差不遠，由實驗四可得知氮氣氣氛幫助了骨材於高溫下黏度的提升，有助於輕質化。燒結體之TCLP量相當低，安全性相當可靠，重金屬總量變化也不大，對環境負荷相當輕微。 Lightweight aggregate was produced by natural expansion material, e.g. pumice, shale, and clay. This study used a municipal solid waste incinerator (MSWI) bottom ash as the material to sinter an artificial lightweight aggregate.Comparing MSWI bottom ash with natural expansion material, we found that the compounds of MSWI bottom ash were complex and heterogeneous. Therefore adding SiO2 and Fe2O3 to the milling of MSWI bottom ash was necessary. And then we used different parameters of sintering to understand the quantity of the expansion gas during the sintering process. The experiment was divided into four parts. First experiment discussed the relation between the quantity of the expansion gas with Fe2O3 when fixed the quantity of MSWI bottom ash and specimens didn’t have deformed during the sintering process. Second experiment fixed the parameters of the sintering and comprehended the influence of adding SiO2. Third experiment, added 10% of fine grain MSWI bottom ash and Fe2O3 to coarse grain MSWI bottom ash, found the effect of adding the fine grain MSWI bottom ash. Final experiment discussed the effect of the form of the artificial lightweight aggregate in the different sintering atmospheres. The compounds of MSWI bottom ash for producing CO2 were more important than adding Fe2O3. In addition the reduction atmosphere was helpful to produce the high quality of the artificial lightweight aggregate.
