https://scholars.lib.ntu.edu.tw/handle/123456789/77078
Title: | 飛灰骨材化技術及其應用之研究 A Study on the Synthetic Stone from Incinerator Fly Ash |
Authors: | 李映松 Li, Ying-Song |
Keywords: | 都市焚化飛灰;穩定藥劑;資源化;抗壓強度;溶出;電漿火炬;MSWI fly ash;stabilized agents;recycling;compressive strength;leaching;torch plasma | Issue Date: | 2009 | Abstract: | 廢棄物處理為一重要之環境課題。垃圾焚化處理可以有效的減少垃圾的體積與重量,為目前臺灣垃圾處理的最適處理方法。臺灣目前已有24座大型焚化廠在運轉,其所產生之灰渣多屬於有害,其中又以飛灰最為嚴重,有重金屬溶出和戴奧辛問題。故焚化爐飛灰(簡稱飛灰)屬於有害事業廢棄物需進一步處理才可進行最終處置。 本研究主要利用水洗、燒結及添加重金屬穩定藥劑等程序處理飛灰,以達到廢棄物減容、無害化及資源化等多重目的。因飛灰中氯化鹽類含量很高,而氯化鹽類的存在會使得重金屬在燒結過程中大量的揮發,造成二次汙染。故本實驗先將飛灰以水洗洗除飛灰中的氯鹽。飛灰水洗後,其重量約減少30 ~ 40 wt.%。經以未調整pH值之毒性特性溶出程序(toxicity characteristic leaching procedure, TCLP)測試水洗灰,其濾洗液(leachate)已符合法規標準。而將TCLP的萃取液調整至約4.5,則重金屬又再度溶出。故又增加添加重金屬穩定藥劑與燒結的步驟。實驗結果顯示飛灰經水洗並添加穩定藥劑後,以5000 psi加壓成形於1150 ℃下燒結一小時,燒結體的抗壓強度高達400 kgf cm-2以上、吸水率約3%,且符合調整pH值之TCLP的標準,可符合臺灣國家標準(CNS)普通磚的規範可做為建築使用。未經壓錠前處理之燒結體亦符合健度測試不會因長時間而造成試體的崩解,檢測其中水溶性氯含量為0.00189%,遠低於預力混凝土的規範0.012%,可做為細粒料使用。本實驗並嘗試以電漿做為熱源,探討其對燒結體的影響,發現電漿不適合運用於燒結處理。 Solid waste treatment is an important environment problem in Taiwan. Incineration can effectively reduce the volume and weight of municipal solid waste (MSW). Twenty-four large incineration plants work in Taiwan. The MSW incineration (MSWI) ashes including bottom and fly ashes are hazardous wastes. For these two ashes, fly ash is most hazardous with heavy metal leaching and dioxin contamination. Thus, it needs further treatment for stabilization and disposal. n this study, the incineration fly ash was stabilized via washing, conditioning and sintering processes. Due to the high content of chlorides in fly ash, it causes high evaporation of metals as the second pollutants during the heat treatment process. The weight loss of fly ash via washing is about 30 ~ 40 wt.%. The results indicate that the washed fly ash (WFA) is already stable under regular toxicity characteristic leaching procedure (TCLP) test without the adjustment the of pH value. However, it does not meet the modified stringent TCLP test with the adjustment of pH value to 4.5. After washing process, the H2SO4, H3PO4 and Na2S were added as stabilization agents to condition the WFA before the sintering process. The dried conditioned sample were then pelletized with a pressure of 5000 psi and sintered at 1150 ℃ for one hour. The resulted sintered cylinders have compressive strengthes over 400 kgf cm-2 and the water absorption of about 3% and meet the more stringent TCLP standard. These pelletized-sintered samples can conform the common bricks standard for the construction purpose of Chinese National Standard (CNS). The sintered sample without pre-pelletization were also conform the soundness of aggregate. The chlorides content of the sample is 0.00189% lower than 0.012% of CNS. It can be used as the raw material of fine concrete. A torch plasma was also used as a heating source for sintering the fly ash in this research. However, the results indicate that it is not suitable for the sintering process because of the disproportionate heat distribution. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/181593 |
Appears in Collections: | 環境工程學研究所 |
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ntu-98-R96541129-1.pdf | 23.53 kB | Adobe PDF | View/Open |
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