| Abstract: | 垃圾焚化處理將產生相當量的灰渣，其中飛灰內含大量易溶出重金屬，需以固化處理，固化後放置於衛生掩埋場，但掩埋場日漸飽和且設置越來越困難的情況下，為使焚化飛灰達到資源循環零廢棄的目標，尋求再利用方法是極為迫切。研究發現垃圾焚化飛灰具有多孔性，在燒結過程中因成份分解而產生大量氣體類似發泡特性，因此本研究利用此特性來燒製多孔調濕陶瓷材料。目前市面上調濕材料的單價均非常高，研發國內自製的調濕陶瓷材料，除了降低售價，又能解決廢棄物處置的問題。
研究分為兩部分，第一部分：焚化飛灰摻配含矽鋁酸鹽的高嶺土依不同比例混和，藉由高嶺土良好的可塑性及成型性，最後高溫燒結製成多孔調濕陶瓷材料。第二部分：添加廢玻璃，玻璃屬於高矽物質及鹼性助熔物，容易於燒結過程中產生液相，燒結後的產品強度大幅增加。所燒製成的試體均需經過調濕試驗，以判斷是否符合標準。試驗方法參照日本JIS A 1470-1：2008建築材料之吸放濕性試驗法─第1部：濕度應答法測定。而評價標準參照日本調濕建材性能評價委員會所訂定之調濕性能評價基準，其吸濕量標準分成3個等級，並且放濕率須超過70 %以上，才能稱為調濕材料。最後確保產品之安全性，參考民國101年環保署公告之「垃圾焚化廠焚化底渣再利用管理方式」作為本研究的規範。
試驗結果水萃灰摻配高嶺土燒結調濕陶瓷材料，得到較佳水萃灰混和比例為70 %(KF-37)，所燒製出的試體均為膨脹現象，也與吸濕量為正相關。最適燒結條件，燒結溫度1,000~1,050 ℃，均可達到第3級最優良調濕材料標準，前12小時吸濕量超過71 g/m2，後12小時放濕率達70 %以上。水萃灰混和比例為50 %(KF-55)，燒結到1,000 ℃，吸濕量為36 g/m2，放濕率為83 %，符合第2級調濕標準。添加玻璃粉最好的配比為廢玻璃：高嶺土：飛灰=6：2：2(GKF-622)，為第2等級，吸濕量為62 g/m2及廢玻璃：高嶺土：飛灰=6：3：1(GKF-631)，為第1等級，吸濕量為30 g/m2，兩者近乎完全放濕。另外添加玻璃的結果強度大幅提升，更超出CNS3299-4 陶瓷面磚試驗法之標準(6.12 MPa)，其值分別為7.25及6.21 MPa。毒性溶出試驗及戴奧辛檢測均低於規範標準，因此可確定此產品無害化並可以進行再生利用。
Municipal solid waste incinerator (MSWI) will produce a great deal of fly ash which contain a large number of heavy metals. The fly ash must be solidified and buried at landfills in Taiwan. Because the landfill is becoming scarce, the goal of zero waste and the resource recycling are imminent issues. This research shows that the MSWI fly ash is porous material which would format air bubbles in sintering process. Therefore, this study would investigate the feasibility of sintering the fly ash as humidity-controlling ceramic. Currently the humidity-controlling ceramic in the market is still expensive. By synthesizing humidity-controlling ceramic, we will provide a cheaper alternative and also reduce the fly ash amount at the same time.
The study consists of two parts: first one, the fly ash and kaolin were mixed in different proportions. Kaolin is a good plasticity material which is helpful for making porous humidity-controlling ceramic. Second one, waste glass powder was added into the mixture of the fly ash and Kaolin, the powder contains a large number of silicon and alkaline fluxing materials that would useful to improve the strength of the sintered specimens after the sintering process. All the synthesized materials have to conform with JIS A 1470-1 of the humidity-controlling test：2008 Determination of water vapor adsorption/desorption properties for building materials Part 1: Response to humidity variation. There are three levels of absorption moisture contents with above 70% of desorption rate, which are the evaluation standard of humidity-control performance of the construction materials. To ensure the safety of the product must meet No. 1010094463A which was announced by Taiwan EPA in 2012.
The study shows that 70% of the fly ash mixes with 30% of Kaoline (KF-37) appears the property of swelling which is positively for absorption moisture content. The optimal sintering temperature is around 1,000~1,050 ℃ of which can meet the third grade of absorption moisture content. 12 hours before, the absorption moisture content is 71 g/m2, and after 12 hours, the desorption rate is XX % (exceed 70 %). 50 % of the mixed rate (KF-55) and sintering at 1,000 ℃, the specimens has 36 g/m2 of absorption moisture content and 83 % of desorption rate that conforms with grade 2 of absorption moisture content. The optimal mixed ratio of waste glass powder, Kaoline and fly ash is 6：2：2 (GKF-622), the absorption moisture content is 62 g/m2 that meet with grade 2 of absorption moisture content. A different proportion of 6：3：1 (GKF-631) can achieve grade 1 which has an 30 g/m2 of absorption moisture content. Both of the two mixture, GKF-622 and GKF-631, almost achieve a completely desorption rate. After adding waste glass powder, the bending strength was increased significantly. The heavy metals of the toxicity characteristic leaching procedure (TCLP) and dioxin detection are all meet with regulation limits of Taiwan, which would confirm the safety and recyclability of this synthesized product. |
