【作者】 周宇；

【导师】 马增益； 严建华；

【作者基本信息】 浙江大学 ， 工程热物理， 2011， 硕士

【摘要】 焚烧处理危险废物是危险废物无害化、减量化、资源化处理的一种主要手段,具有显著的减容减重优势,并能回收热能,是目前国内外广泛采用的危险废物的处理方式,然而焚烧过程易产生富含重金属的焚烧飞灰进而造成二次污染,并被归类为危险废物,必须进行特殊处理。危险废物焚烧飞灰的熔融处理技术为焚烧飞灰的处理处置提供了新的途径。本文针对危险废物焚烧飞灰,开展了飞灰熔融处理技术的基础研究。对飞灰的理化特性、微观形貌、物相组成、浸出毒性等进行了系统的分析。危险废物焚烧飞灰外观松散,比表面积大,成分复杂,主要成分为SiO2、CaO、Na2SO4并有一定量的重金属Cr、Ni、Cu、Zn、Cd、Pb等,其中Pb的浸出浓度超过国家固体废物浸出毒性鉴别标准。利用热重-差热分析对飞灰熔融的历程进行了研究,在自行设计的小型实验台上进行熔融实验,考察了气氛条件、CaO、SiO2作为添加剂对飞灰熔点的影响,并以碱度作为添加剂效果的判据。危险废物焚烧飞灰熔融处理技术所要解决的另一问题是消除重金属的潜在危害。对飞灰熔融过程中典型重金属的迁移特性进行了考察。对熔融温度、添加剂、反应气氛等因素对重金属固定率的影响进行了系统研究。结果显示,飞灰经过熔融处理后,结构更加致密,重金属的浸出浓度远远低于飞灰,达到了无害化的目的。更多还原

【Abstract】 Disposing of Hazardous Waste (HW) by incineration has been an increasingly adopted technology all over the world due to its advantages of remarkable volume-reduction, weight-reduction and energy-recovery. But the fly ash brought by incineration is listed as hazardous waste for its high leaching toxicity of heavy metals, and should be particularly treated. Melting treatment technique becomes one of the most significant research communities.Fundamental research of hazardous waste incineration fly ash melting technique was done in this paper. The properties of fly ash sample such as physical and chemical characteristics, micro-morphology, mineralogical characteristics, leaching toxicity were analyzed, and the results show that the appearance of fly ash samples is loose and the specific surface area is large. SiO2, CaO, Na2SO4 are the principal components, and there are a little content of heavy metals as well. The leaching toxicity of Pb exceeded greatly compared with the national standard.The processes of melting were characterized through the TGA-DSC system. The other experiments were conducted in a self-developed furnace system and mainly focused on the analysis of influence of melting point by the additional reagent and the atmosphere, and the alkalinity criterion was set up.The partition of heavy metals during melting process was also studied in this paper, and the influences of temperature, atmosphere, and the additional reagent was systematically analyzed. The results showed that after the melting of fly ash, the microstructure of slag turned to be much more impact and the leaching toxicity of heavy metals was sharply reduced and could be safely land filled.更多还原