本計畫針對國內漸趨普遍的再生燃料使用於燃煤鍋爐混燒所產生之灰渣進行水泥系材料資源化再利用研究，預定採用之混燒再生燃料包括：(1) 紡織汙泥、(2) 廢塑膠混合物RDF、(3) 廢輪胎膠片、及(4) 漿紙汙泥等幾種工業廢棄資源，用於燃煤鍋爐輔助燃料混燒時所產生之灰渣，將其應用成為混凝土之輔助膠結材料或再生粒料進行評估，以供主管機關針對混燒灰渣管制或開放再利用用途之參考依據。 首先對國內燃煤鍋爐使用再生燃料之現況進行調查，並對實際執行混燒作業之工業鍋爐進行分類及採樣，包括紡織汙泥、廢塑膠混合物RDF、廢輪胎膠片、漿紙汙泥等再生燃料，配合單純燃煤以及再生燃料與煤混燒等兩種操作方式，取得具有代表性的灰渣樣本，進行混燒鍋爐灰渣物理、化學基本特性的測試，並依據基本性質試驗結果，研判衍生飛灰、底渣分別作為混凝土輔助膠結材料、再生粒料之潛力，以及後續進行研磨或其他再處理之品質提升需求。考慮之重點，除了常用作為卜作嵐材料的規範項目如化學組成、細度及強度活性指數以外，需要針對再生燃料所產製混燒灰渣之品質穩定性，以及鍋爐飛灰常見的含硫量偏高等不利因素，進行混燒再生燃料鍋爐衍生灰渣再利用為輔助膠結材料或再生粒料的綜整性優、缺點分析，以及再處理或品質提升之可行性，並建立客觀的混燒灰渣再利用品質標準，以提供主管機關執行事業廢棄物管理決策之參考依據。 ;This study plans to investigate the potential of boiler ashes, including fly ash and bottom ash, produced from co-firing coal and industrial by-products in coal-burning boilers as supplementary cementitious materials or recycled aggregate for making concrete. Four possible sources of industrial by-products as supplementary fuels have been selected, including (1) textile-manufacturing sludge, (2) waste plastics RDF, (3) waste tire chips, and (4) paper-making sludge. The aim is to evaluate the potential of using co-firing boiler ashes as supplementary cementitious materials or aggregate in making concrete. The study will start with investigating current status of industrial by-products as supplementary fuels for coal-burning boilers in the industry. Representative boiler ash samples produced from boilers co-firing coal and industrial by-products will be collected for basic characterization tests such as specific gravity, sieving, adsorption, pH, and chemical contents. Based on the basic characteristics of ashes obtained from co-fired boilers, an evaluation on the potential of these ashes as supplementary cementitious materials/aggregate will be assessed, and the need for further treatment of the raw material will also be considered. The focus of the evaluation includes not only the general criteria used for pozzolanic materials/aggregate, but also the variability in the quality of these ashes and the high sulfur content commonly encountered on boiler ashes. These 2 factors are, actually, critical for potential application of these ashes as supplementary cementitious materials/aggregate to concrete-making. The results of the study will be summarized such that the pros and cons of such application can be disclosed and an objective criteria established on the quality standards of co-fired boiler ashes for use as concrete making materials. The finding will help the administrative authority in drawing up the codes in the management of the boiler ashes derived from boilers co-firing coal and by-product supplementary fuels.
