【作者】 杨福云；

【导师】 刘清才；

【作者基本信息】 重庆大学 ， 冶金工程， 2005， 硕士

【摘要】 本文采用冶金、物理和化学等理论与方法研究了重庆市同兴垃圾焚烧厂布袋式除尘器收集飞灰的物理化学特性、金属元素的存在形态和特性。 对飞灰的湿度、吸水性、微观结构、化学组成、颗粒尺寸分布、重金属含量进行测试分析，研究了pH值对重金属浸出毒性的影响。结果表明：飞灰浸出液中锌、铅、镉的浓度高于固体废物浸出毒性鉴别标准；随着浸取液pH值的升高，浸出液中重金属浓度逐渐降低，并且pH在4.5～7.5之间时，重金属浓度变化较大。 研究添加不同粘结剂和养护时间对飞灰成球性能和抗压强度的影响。分析了飞灰成型的最佳工艺条件。用水泥作粘结剂时，飞灰球团抗压强度随水泥加入量的增大而不断增大，随养护时间延长而提高，适宜的水泥添加量为6％左右，养护期为8天左右，其抗压强度为500-550N／球；消石灰具有很好的固化能力，适宜的添加量为7％，适宜的固化时间为12天左右；在本实验条件下，最佳粘结剂为3％消石灰加1％工业糖浆，养护时间为11天左右，其抗压强度为550-600N／球。采用添加6％水泥、3％消石灰加1％工业糖浆作为粘结剂，其强度均能满足熔融分离处理过程要求。对此两种飞灰球团进行重金属浸出毒性实验，结果显示各种重金属的浸出浓度均低于固体废物浸出毒性鉴别标准。 实验研究和分析了上述两种飞灰球团中金属元素熔融分离效果，研究熔融温度、熔融时间、金属熔池配比及碱度对重金属分离效果的影响，为垃圾焚烧飞灰金属元素熔融分离无害化处理提供工艺方法和参数。结果表明：飞灰中重金属脱除率随熔融温度升高而升高，随碱度的增大呈现先增后降的趋势，随金属熔池配比的增加而增加，熔融时间对重金属脱除率影响效果不显著。飞灰中重金属分离的适宜条件为：熔融温度1400℃，熔融时间10min，球团碱度1.8(二元碱度)，金属熔池与飞灰球团比例为5：4。在此实验条件下，重金属的脱除率均在95％以上。 在熔融过程中，飞灰有一定的重量损失，其损失率均随熔融温度和时间的提高而增大，而碱度和金属熔池配比对其影响不明显。对反应后灰渣做重金属浸出毒性实验，发现重金属浸出量远远低于浸出标准，有些重金属未检测出，无害化效果非常明显。更多还原

【Abstract】 The metallurgic, physical and chemical theories and methods have been used to study on the physical and chemical characteristic of the fly ash gathered under fabric filter in Tongxing Municipal Solid Waste Incineration (MSWI) plant, Chongqing city. Meanwhile, the existing forms and characteristics of metallic elements in the fly ash have also been researched.The properties of fly ash including humidity, water absorption, microstructure, chemical composition, particular size distributing, heavy-metal content and effects of heavy-metal leaching characteristic by pH value are studied by experiments. The results show that the concentration of zinc, lead and cadmium exceed Solid Waste Leaching Character Standard. With pH value of leaching liquid increasing, the concentration of heavy-metal in leaching liquid decrease. When the pH value is 4.5~7.5, the concentration of heavy-metal changes largely.Adding the different binders in different period will affect the shaping properties and compressive strength of fly ash. The optimal technology of shaping has been attained in this paper. Adding cement as binder, the compressive strength of fly ash pellets will rise with cement content and curing period increasing. The suitable cement content is about 6% and curing period is about 8 days while the compressive strength is 500-550N/bellet. The hydrated lime has good solidifying capability. The suitable The hydrated lime content is about 7% and curing period is about 12 days. In the experimental conditions, the optimal technology is adding 3% hydrated lime and 1% industrial syrup and its curing period is about 11 days while the compressive strength is 550-600N/bellet. Adding 6% cement or 3% hydrated lime and 1% industrial syrup as binders, its compressive strength can satisfy melting strength. Moreover, that two kinds of pellets have been tested for the leaching characteristic. The results show that the value of leaching concentration is smaller than Chinese Standard, and that the fly ash was solidified well.The metals in fly ash pellets separating effects are studied by experiments. How the melting temperature, period, metal melting bath proporsition and basicity affect heavy-metal separating are studied and analysed, which provide a technological method and parameter for metal in MSWI fly ash disposing. The results indicated that the removal rate of heavy metal in the fly ash increased along with the temperature更多还原