论文总字数：36911字

摘 要

城市垃圾焚烧飞灰作为危险废弃物，在处理利用的过程中尤其要注意重金属等污染物的渗透。飞灰中的盐类对污染物稳固化有害，而水洗能够脱除飞灰中大部分盐类。水洗工序的脱溶效果受到多种因素的影响，地质聚合物的强度和对重金属的稳固化效果也需要探究。

本实验以垃圾焚烧飞灰、稻壳灰、二次铝灰为原材料，以氢氧化钠为碱激发剂，制备地质聚合物。首先探究了水洗脱溶效果随着液固比、搅拌机转速与浸取时间的变化规律，得出各个因素的最佳值。并设计了正交试验探究各个因素在综合条件下对脱溶效率的影响，得出综合情况下的最佳实验条件。在得出的最佳实验条件下对原灰进行水洗，利用水洗灰和二次铝灰、热处理过的稻壳灰进行不同比例混合搅拌、制样，并进行为期7天的自然养护，探究了硅铝摩尔比、碱激活剂添加量对碱激发地质聚合物的性能和重金属稳固化效果的影响，实验结论如下：

脱溶效率随着液固比升高而增加，随着浸出时间先升高后趋于平缓，随着转速提高先增加后降低。综合实际应用中的经济性因素，最终取最佳液固比为5:1，最佳浸取时间为15 min，最佳工作转速为1000 r/min。 正交试验取得相同结果，且得出对脱溶效率的影响大小液固比gt;浸取时间gt;转速。

以水洗灰、稻壳灰、二次铝灰为原料制备固化体，在减小硅铝摩尔比和增加碱激活剂量的过程中，地质聚合物的抗压强度和重金属的浸出浓度均呈现先缓慢上升后上升速度加快的趋势，最大抗压强度为1.698 Mpa，重金属中Cr稳固化效率最高，达到99.9%。综合经济性和实验效果取最佳硅铝比为0.92，最佳碱激活剂添加量为6%。

对固化体进行XRD分析，Ca₂(SiO₄)、Na₇[Al₅Si₇O₂₄]CO₃.H₂O和Ca₂Al₂SiO₆(OH)₆等新相的出现说明地质聚合反应的成功进行。

关键词：垃圾焚烧飞灰，水洗预处理，重金属浸出，地质聚合物, 稳固化。

Abstract

Municipal solid waste incineration fly ash(MSWIFA) , regarded as a kind of hazardous waste, often leaches pollutants including heavy metals in the process of treatment and utilization. The salt in fly ash is harmful to the stabilization of pollutants, and washing, a pretreament method, can effectively remove most of the salt in fly ash. The removal efficiency of washing process is affected by many factors, and the strength of geopolymers and the stabilization effect of heavy metals also need to be explored.

In this experiment, we used MSWIFA, rice husk ash and secondary aluminum ash as raw materials, and sodium hydroxide as alkali activator to prepare geopolymers. Firstly, we studied the change rule of water removal effect with solid-liquid ratio, rotating speed of mixer and leaching time to get the optimum value of each factor. We designed orthogonal experiment to explore the influence of various factors on the removal effect in order to get the best experimental conditions under comprehensive conditions. Washing MSWIFA under the obtained optimum experimental parameters, prepare sample with mixture of heat-treated rice husk ash and secondary aluminum in different proportion, after seven day’s natural curing, we get the solidified body. We investigated the effects of the molar ratio of Si-Al and the amount of alkali activator on the on the compressive strength and heavy metal stabilization of the solidified body. The experimental results are as follows:

The removal effect increased with the increase of the liquid-solid ratio, increased first and then tended to be flat with the leaching time, and increased first and then decreased with the increase of the rotating speed. Based on the economic factors in practical applications, the optimum liquid-solid ratio was determined to be 5:1, the optimum leaching time was 15 min, and the optimum operating speed was 1000 r/min. The same results were found in orthogonal experiment, and the influence on the solubilization efficiency was obtained as liquid-solid ratiogt;leaching timegt;rotating speed.

In the process of decreasing the molar ratio of si-al and increasing alkali activation dose, both leaching concentration of heavy metals and the compressive strength of geopolymer showed a trend of increasing slowly at first and then accelerate. The maximum compressive strength was 1.698 Mpa, and the stabilization efficiency of Cr reached the highest at 99.9%. The optimum Si-Al ratio was 0.92 and the optimum content of alkali activator was 6%.

The results of XRD analysis of the solidified body showed that the emergence of new phases such as Ca₂(SiO₄), Na₇[Al₅Si₇O₂₄]CO₃.H₂O and Ca₂Al₂SiO₆(OH)₆ indicated the successful formation of geopolymers.

Keywords: municipal solid waste incineration fly ash, washing pretreatment, heavy metal leaching, geopolymers, stabilization

目 录

摘要 I

Abstract II

第一章 绪论 1

1.1 研究背景与意义 1

1.1.1城市生活垃圾焚烧飞灰的产生及其危害 1

1.1.2 垃圾焚烧飞灰的水洗预处理及无害化处理技术 2

1.2地质聚合物及地质聚合物对重金属的稳固化效果 4

1.2.1地质聚合物及对重金属的稳固化 4

1.2.2基于稻壳灰的地质聚合物研究 6

1.2.3相关国内外研究现状 7

1.3 研究内容 9

1.3.1研究内容与研究目标 9

1.3.2研究技术路线 10

1.3本章小结 10

第二章 实验装置及方法 12

2.1实验材料及实验仪器设备 12

2.1.1 实验材料与实验试剂 12

2.1.2实验设备与仪器 13

2.2实验操作流程与实验系统 14

2.2.1实验操作流程 14

2.2.2水洗预处理试验系统 14

2.2.3飞灰稳固化反应实验系统 15

2.2.4 重金属毒性浸出测试系统 15

2.2.5 XRD与XRF系统 16

2.3实验方法 17

2.3.1试验样品保存方法 17

2.3.2水洗预处理方法 17

2.3.3抗压强度测试方法 18

2.3.4 重金属毒性浸出及浓度测量方法 19

2.4 本章小结 20

第三章 水洗预处理参数对脱溶效率的影响规律 21

3.1水洗预处理参数对脱溶效率的影响规律 21

3.1.1水洗预处理中三个因素对脱溶效率的影响。 21

3.2探究水洗预处理的最优工艺参数 23

3.3本章小结 25

第四章 地聚物参数对垃圾焚烧飞灰稳固化及资源化处置的影响 26

4.1 碱激活剂添加量对垃圾焚烧飞灰稳固化及资源化处置的影响 28

4.1.1碱激活剂添加量对固化体抗压强度的影响 28

4.1.2碱激活剂添加量对重金属稳固化效果的影响 29

4.2硅铝摩尔比对垃圾焚烧飞灰稳固化及资源化处置的影响 31

4.2.1硅铝摩尔比对固化体抗压强度的影响 31

4.2.2硅铝摩尔比对重金属浸出浓度的影响 32

4.3 水洗飞灰及固化体晶体结构对比 34

4.4 本章小结 35

第五章 结论与展望 36

参考文献 38

致 谢 42

第一章 绪论

1.1 研究背景与意义

1.1.1城市生活垃圾焚烧飞灰的产生及其危害

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