论文总字数：40272字

摘 要

脱硫灰是钢铁行业中烧结烟气脱硫处理后而产生的副产物，自身性质不稳定，大多是抛弃堆放处理，会造成对土壤及水资源的二次污染。因此，脱硫灰亟待科学处置和资源化利用。本文研究钢厂脱硫灰改性软黏土的路用性能，分析其用于路基填料的可行性，寻找脱硫灰综合利用的新途径，变废为宝。

本文以钢厂脱硫灰以及黏土的混合料为研究对象，通过对混合料成分原材料性质、物理-力学性能等一系列室内试验分析的基础上，对钢厂脱硫灰改性黏土的性质和强度以及微观机理等进行研究，探究钢厂脱硫灰改性黏土的强度特性，并进行材料优化配比，筛选出最优配比，提出新型改性材料，取得以下主要研究成果和结论：

1. 在本研究所设置脱硫灰在改性土中的掺量范围内，即0%~8%，随着脱硫灰掺量的提高，改性土液、塑限均上升，而塑性指数先减小后增加，同时改性土最佳含水率上升，最大干密度下降。
2. 增加改性土中的脱硫灰掺量，可以显著提高其承载比（CBR）。改性土的强度较高，CBR可以满足路基填料的强度要求。
3. 6%掺量的脱硫灰改性土其7d无侧限抗压强度最大，为0.76MPa，对黏土的强度提高效果显著。
4. 改性土中脱硫灰与黏土的最优配比为1:16。
5. 脱硫灰改性土可以改善黏土内部结构松散的缺点，脱硫灰与黏土通过发生相应的反应，将黏土颗粒凝聚起来，以此提高改性土的强度。

关键词：脱硫灰综合利用；改性土；路用性能；材料优化配比；微观机理。

Abstract

Desulphurization ash is a by-product of sintering flue gas desulphurization treatment in iron and steel industry. It is unstable in nature. Most of the desulphurization ash is discarded and dumped, which will cause secondary pollution to soil and water resources. Therefore, desulfurization ash urgently needs scientific disposal and resource utilization. This paper studies the road performance of soft clay modified by desulfurized ash in steel works, analyses the feasibility of using desulfurized ash as roadbed filler, and seeks a new way of comprehensive utilization of desulfurized ash to turn waste into treasure.

In this paper, the desulfurization ash and clay mixture are taken as research objects. Based on a series of laboratory tests and analysis of raw material properties and physical-mechanical properties of the mixture, the properties and strength of the desulfurization ash modified clay in steel plant and micro-mechanism are studied. The strength characteristics of the desulfurization ash modified clay in steel plant are explored, and the optimum proportion of materials is screened out. The main research results and conclusions of the new modified materials are as follows:

(1) In the range of desulfurization ash content of modified soils set up in this paper, with the increase of desulfurization ash content, the liquid and plastic limit of modified soils increase, while the plastic index decreases first and then increases, at the same time, the optimum moisture content of modified soils increases, and the maximum dry density decreases.

(2) Increasing the content of desulfurized ash in the modified soil can significantly increase its load-bearing ratio (CBR). The strength of modified soil is higher, and CBR can meet the strength requirements of roadbed filling.

(3) The unconfined compressive strength of desulfurized ash modified soil with 6% content is the highest in 7 days, which is 0.76 MPa. The effect of improving the strength of clay is remarkable.

(4) The optimum ratio of desulfurized ash and clay in modified soil is 1:16.

(5) Desulfurized ash modified soil can improve the weakness of loose internal structure of clay. Desulfurized ash and clay can agglomerate clay particles through corresponding reaction, so as to improve the strength of modified soil.

Keywords：Comprehensive Utilization of Desulfurized Ash; Modified Soil; Road Performance; Optimum Material Proportion; Microscopic mechanism.

目 录

摘要 I

Abstract II

第一章 绪论 1

1.1研究背景及意义 1

1.2研究现状分析 2

1.2.1半干法脱硫技术 2

1.2.2脱硫灰污染现状 3

1.2.3国外研究现状 4

1.2.4国内研究现状 4

1.3主要研究内容 5

1.4研究技术路线 6

第二章 试验材料与试验方法 7

2.1试验概述 7

2.2试验材料 7

2.2.1脱硫灰材料 7

2.2.2低液限黏土 8

2.3试验内容与方法 10

2.3.1 基本物理性质试验 10

2.3.2 击实试验 12

2.3.3 承载比（ CBR）试验 13

2.3.4 无侧限抗压强度（UCS）试验 17

2.3.5 扫描电镜（SEM）试验 19

第三章 脱硫灰改性土基本物理性质研究 20

3.1本章概述 20

3.2 试验结果及分析 20

3.2.1 改性土的液塑限研究 20

3.2.2 改性土的最佳含水率和最大干密度研究 25

3.3 本章小结 29

第四章 脱硫灰改性土力学性能研究 30

4.1 本章概述 30

4.2 试验结果及分析 30

4.2.1承载比试验研究 30

4.2.2 无侧限抗压强度试验研究 34

4.3本章小结 35

第五章 脱硫灰改性土微观结构研究 37

5.1 本章概述 37

5.2 试验结果及分析 37

5.3 本章小结 40

第六章 结论及展望 41

6.1 本文主要结论 41

6.2 研究工作展望 41

参考文献 43

致 谢 47

附录 48

第一章 绪论

1.1研究背景及意义

钢铁行业是我国重要的基础行业，同时也是高消耗、高污染、高排放的源头行业^[1]。在我国钢铁行业中，二氧化硫主要来源于烧结和球团烟气，而烧结工艺过程中排放的SO₂量约占钢铁企业生产系统的40%~60%。因此，控制烧结过程中SO₂的排放是控制我国大气污染的重中之重^[2]，也是钢铁企业SO₂污染控制的重点。同时，“十三五”钢铁行业SO₂减排目标和“十三五”减排规划的提出，进一步推动了我国钢铁企业配套建设烧结烟气脱硫项目的实施。

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