关于MSWI飞灰由复合活性化水泥材料固化/稳定性的研究
Pengyue Su1, Ming Xia1,2, Kunping Chen1
1School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang 222005, China.
ACS omega
|February 24, 2025
概括
城市固体废物焚烧 (MSWI) 飞灰 (FA) 可以使用复合活性化水泥材料安全处理. 这种方法有效地固定重金属,减少环境风险,并显示出出色的机械性能.
科学领域:
- 环境科学 环境科学
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
背景情况:
- 城市固体废物焚烧 (MSWI) 飞灰 (FA) 是一种含有重金属的危险废物,由于漂水而带来重大环境风险.
- 有效处理和稳定MSWI FA对于环境安全和可持续废物管理至关重要.
- 目前的方法需要改进,以解决FA的危险性和防止重金属污染.
研究的目的:
- 开发和评估用于MSWI FA重金属固化和稳定复合活性化水泥材料的复合材料.
- 研究最佳的混合设计和固化条件,以实现固化材料中优异的机械性能.
- 阐明准备的复合材料中的重金属固定机制.
主要方法:
- 使用高炉渣,FA和MSWI FA.制备复合活性化水泥材料.
- 优化MSWI FA含量,水玻璃模量,液体-固体比率和固化温度.
- 使用标准化测试对机械性能 (压力强度) 和重金属液 (Pb,Cd,Cu) 的评估.
- 使用XRD,FTIR和SEM-EDS分析对固化矩阵和重金属固定机制的表征.
主要成果:
- 最佳成分 (30% MSWI FA,水玻璃模量1.0,液体固体比为0.32,45°C固化) 产生了固化体,其压力强度为41.9 MPa.
- 观察到重金属 (Pb,Cd,Cu) 的浸出度和非残留状态显著降低.
- XRD,FTIR和SEM-EDS分析证实,重金属主要通过物理封装和化学结合来固定.
结论:
- 复合活性化水泥材料对于MSWI飞灰的安全处理和稳定是有效的.
- 开发的材料具有出色的机械性能,并大大减少了重金属的漏.
- 固定机制涉及物理封装和化学结合的组合,确保长期稳定性.
更多相关视频
相关概念视频
Pozzolans
97
Pozzolans are siliceous or aluminous materials blended with Portland cement. They interact with the calcium hydroxide produced during the hydration of Portland cement and contribute to improved strength and durability of concrete. The pozzolanic activity, a measure of a pozzolan's effectiveness, is typically assessed using the strength activity index, as defined in ASTM C 618-93, which calculates the ratio of the compressive strength of cement mixtures with and without pozzolan.
Fly ash is...
Fly ash is...
97
Alkali Aggregate Reaction in Concrete
83
The alkali-aggregate reaction in concrete involves natural siliceous minerals in aggregates reacting with alkaline hydroxides derived from cement alkalis. This reaction forms an alkali-silica gel that absorbs water, swells, and increases in volume, which is confined by the surrounding cement paste, creating internal pressures that crack and disrupt the concrete. The extent of expansion and damage can be partly attributed to the alkali-silica reaction's osmotic hydraulic pressure and the...
83
Hydration of Cement
191
Hydration of cement is a chemical reaction between cement particles and water. This process occurs primarily through two mechanisms: through-solution and topochemical. In the through-solution process, anhydrous compounds dissolve into their constituents, hydrates form in the solution, and then precipitate from the supersaturated solution. The topochemical process involves solid-state reactions at the cement particle surface. The through-solution process dominates the topochemical process at the...
191
Types of Cement II
88
Portland blast-furnace cement is made by blending Portland cement clinker with granulated blast-furnace slag, which accounts for 25 to 65 percent of the cement's weight. Despite its similarities to ordinary Portland (Type I) cement in terms of fineness and setting times, its early strength is lower, though it achieves comparable strength later on. It's particularly suited for mass concrete structures and marine environments due to its lower heat of hydration and superior sulfate...
88
Additives and Fillers in Concrete
87
Additives and fillers are integral to enhancing the properties of concrete. Pozzolans and blast-furnace slag are additives or admixtures due to their reactions with calcium hydroxide released during cement hydration. Fillers, which are finely ground and similar in fineness to Portland cement, improve concrete attributes such as workability density, and reduce capillary bleeding or cracking. Some fillers possess hydraulic properties or participate in benign reactions within the cement paste.
The...
The...
87
Accelerators
70
Accelerators in concrete serve as admixtures to speed up the hardening process, enabling the concrete to achieve early strength faster. Although accelerators do not necessarily impact the time it takes concrete to set, they reduce this time in practice. A common accelerator is calcium chloride, which is particularly useful for hastening early strength development in cold weather or for rapid repair jobs that require quick heat generation after mixing.
The effectiveness of calcium chloride can...
The effectiveness of calcium chloride can...
70


