| 摘要: | 目前台灣地區的都市垃圾主要採取焚化處理為主，相對的也產生大量的焚化灰渣問題，於一些先進的國家，已將把焚化底渣視為一種可資源化的產品。本研究主要探討粗粒徑底渣燒製高強度之輕質骨材，使底渣具有較高的經濟價值。
底渣經兩段水洗後以200號篩篩分，#200以上的部分先經顎碎機顎碎成8mm後進行濕式球磨，而細粒徑的部份則留下將其視做為調質的材料。粗粒徑底渣經前處理後，以不同比例之發泡劑(SiO2、Fe2O3)及5%的細粒徑添加到10克的粗粒徑底渣中做為調質，燒結溫度為1100℃，以人工方式造粒成圓球狀。
由實驗結果得知，10克粗粒徑骨材僅添加0.1~0.4克Fe2O3即可燒製出密度低於1.6 g/cm3、強度在100kgf/cm2的輕質骨材。SiO2以添加1、2.5克和少量的Fe2O3可燒製出較理想的輕質骨材，密度皆小於1.6 g/cm3，含水率大都小於10%，而抗壓皆大於175 kgf/cm2屬於高強度骨材可做為結構性輕質混凝土。而添加了5%的細粒徑底渣所燒出之骨材其密度較未添加者低，但含水率相較之下稍高，由以上工程性質發現底渣為燒結高強度輕質骨材的良好材料，可以做為經濟價值較高的資源化材料。
At present, incineration is the major treatment way of the municipal solid waste in Taiwan, while it produced large amount of ash and residuals should be handled carefully. Bottom ash was usually recovered as the aggregates of construction engineering in many developed countries, but the heavy metals are not stable enough in the field, it will influence the value during the recovering and reusing. This study is aim to explore the feasibility to regenerate the lightweight aggregate by sintering of the coarse grain of MSWI bottom ash, in order to stabilize the heavy metals and increase the reusing value of bottom ash.
Bottom ash was extracted twice by water, sieved with 200# mesh (0.074mm) to separate the coarse grain form fine grain. The former was milled to particle size less then 8 mm, while the later was using as the adjuvant agent during the experiment. Foaming agent (SiO2、Fe2O3) were added in different proportion relatively, and 5% fine grain was blended into coarse grain, pressed to form pellet manually, and then sintering at 1100oC.
The result showed that, addition of 0.1~0.4 g Fe2O3 into 10 g coarse grain could generate lightweight aggregate with density less then 1.6 g/cm3, compressive strength greater then 100 kgf/cm2, while addition of 1~ 2.5 g SiO2 and few Fe2O3 can generate better product with density less then 1.6 g/cm3, water absorption less then 10%, and compressive strength greater then 175 kgf/cm2. These products all satisfied the criteria of high-strength aggregate, which could be used in the structural lightweight concrete. Light-weight aggregate sintering with 5% fine grain bottom ash can be sintered to lower density, but has higher water absorption rate. In conclusion, sintering of high-strength aggregate with coarse grain MSWI bottom ash after proper pretreatment and blending is feasible; it could elevate the safety and vale of the product evidently during the management of ashes |
