基于硅基的垃圾焚烧飞灰中温热处理重金属稳固化实验

发布时间：2018-01-28 10:44

  本文关键词： 垃圾焚烧 飞灰 热处理 重金属 稳固化　出处：《化工进展》2017年09期 　论文类型：期刊论文

【摘要】：向垃圾焚烧飞灰(MSWI FA)中分别添加硅灰、硅溶胶、石英砂与一定比例的水,混合均匀并进行热处理。研究了添加物种类、热处理温度对垃圾焚烧飞灰中重金属浸出特性的影响,分析了飞灰热处理过程中重金属化学形态、晶体结构和微观形貌的变化。结果表明:热处理过程中,硅灰和硅胶与飞灰中的钙基物质反应生成CaSiO_3、Ca_2SiO_4、Ca_3SiO_4Cl_2、Ca_3Fe_2(SiO_4)3以及氢氧硅磷灰石等硅酸盐相,转变了重金属的化学形态,将重金属稳固在硅酸盐晶格中,降低了飞灰的浸出毒性;在硅灰添加量为10%或JN-40硅胶添加量25%,热处理温度600℃条件下,热处理1h后,飞灰中Pb的浸出浓度由11.91mg/L分别降至0.79mg/L和0.78mg/L,Cd的浸出浓度由3.18mg/L分别降至0.09mg/L和0.10mg/L;热处理过程中Cr的浸出浓度有所上升但未超出生活垃圾填埋场控制标准。
[Abstract]:Silica fume, silica sol, quartz sand and a certain proportion of water were added to MSFAWI to incinerate MSWI, and the mixture was homogenized and heat treated. The effect of heat treatment temperature on the leaching characteristics of heavy metals in fly ash from MSW incineration was studied. The changes of chemical morphology, crystal structure and microstructure of heavy metals in fly ash during heat treatment were analyzed. Silica fume and silica gel react with calcium based substances in fly ash to form CaSiOs, Ca2SiOs, Ca2SiOs, Ca3SiO4Cl2. The chemical forms of heavy metals were changed in the silicate phases such as Ca_3Fe_2(SiO_4)3 and hydroxysilicate apatite. The heavy metals were stabilized in silicate lattice and the leaching toxicity of fly ash was reduced. When the amount of silica fume is 10% or the amount of JN-40 silica gel is 25%, the heat treatment temperature is 600 鈩，

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