濕式研磨對MSWI飛灰特性影響之研究

The wet ball milling effects on the particle characteristics of MSWI fly ash

莊家榮(Chia-Jung Chuang)

指導教授 ： 高思懷

淡江大學/工學院/水資源及環境工程學系碩士班/碩士(2006年)

https://doi.org/10.6846/TKU.2006.00372

摘要

都市垃圾焚化飛灰是一種性質複雜，不易處理之有害廢棄物，目前台灣地區對都市垃圾焚化飛灰處理方式多採固化程序進行最終處置，但固化後體積增大，且重金屬有再溶出之疑慮，因此穩定飛灰中有害物質及進行再利用處理技術為未來趨勢。
本研究主要探討濕式研磨對水洗後飛灰粉體之影響，分別使用粒徑分析儀、X-ray粉末繞射儀、掃描式電子顯微鏡等儀器，來分析粉體研磨前後之性質差異與變化，並且使用毒性特性溶出程序與序列萃取兩種實驗方法，來了解重金屬鉛隨研磨時間的溶出量與型態變化，以利於粉體後續之使用及研究方向。
由實驗結果得知，飛灰經由水洗後，可以降低飛灰中氯鹽含量及重金屬鉛溶出量，然後藉由粒徑分析儀、SEM、XRD等分析探討濕式研磨後之粉體，找出最佳磨球比例為1：1、礦漿濃度10%、磨罐轉速93rpm、研磨液乙醇，而研磨後粉體性質除了縮減粉體粒徑外，從SEM觀察發現微米粒子是由更小之細微顆粒所組成，晶相物種波峰強度則會隨著研磨時間減弱，並再次降低重金屬鉛TCLP溶出濃度且符合法規值，因此研磨對於鉛TCLP溶出有穩定之效果，後續研究使用磷酸為研磨液，從序列萃取結果發現磷酸可以使鉛型態趨於穩定不溶出，同時讓研磨液鉛濃度與粉體中鉛溶出量均符合法規標準，確實達到穩定化效果。

關鍵字

飛灰 ； 水洗 ； 研磨 ； 重金屬 ； 磷酸 ； 穩定

並列摘要

Municipal solid waste incinerator (MSWI) fly ash is defined as hazardous waste, which is difficult to be handled due to its complicate composition. At present, all of them are treated by solidification/stabilization and then landfill in Taiwan. But the specimen occupied the landfill site and the heavy metals re-leaching in long-term still are the problems. Ball milling to super-fine particle could enhance the chemical reaction in the treatment, applying it on the stabilization of the heavy metals in fly ash, is anticipative to promote the opportunity of recovery and reusing.
The study is to research the characteristic of water extracted fly ash followed by wet ball milling. By using of Particle Size Analyzer, X-ray Diffraction, Scanning Electron Microscope to identify the property of fly ash, then use toxicity characteristic leaching process (TCLP) and sequential extraction procedure (SEP) to analyze the leaching characteristics and bonding pattern of heavy metals.
The results showed that, water-extraction could effectively reduce the chloride content, and leaching potential of Pb in fly ash. The optimum grinding condition in the experiment is：solid of slurry by weight is 10 %, rotation rate of milling jar is 93 rpm, and the milling dispersion solution is alcohol, the mixing ratio of milling media is 1:1(diameter of milling media is 5 and 15 mm respectively). After milled, particle size of water-extracted fly ash reduced gradually to micrometer grade detected by Ultra Particle Analyzer, but based on SEM observations, these micro-particles actually composed of smaller motes. The peak intensity of XRD decreased as increasing of milling time. In addition, leaching potential of Pb could be reduced to fit TCLP regulation after milling operation; it proved that the milling operation has the ability to stabilize Pb in fly ash. Appling phosphoric acid solution as the milling fluid and analyzing the product by SEP, the results showed that Pb can be stabilize as hard-to-leaching bounding type.

並列關鍵字

fly ash ； water-washed ； mill ； heavy mental ； phosphoric acid ； stabilize

參考文獻

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