首页|利用生活垃圾焚烧飞灰制备膨胀胶凝材料的试验研究

利用生活垃圾焚烧飞灰制备膨胀胶凝材料的试验研究

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为实现生活垃圾焚烧飞灰在建材领域的大规模资源化利用,研究了飞灰掺量、水灰比以及外加剂对飞灰-水泥膨胀胶凝体系性能的影响,并对水化产物进行微观分析.结果表明:随着垃圾焚烧飞灰掺量的增加,飞灰-水泥料浆扩展度减小,凝结时间延长,抗压强度持续降低,膨胀率呈先增大后减小的趋势,且当飞灰掺量为 60%时取得最大值;随着水灰比的增大,料浆扩展度、凝结时间及膨胀率均增加,水灰比取 0.37～0.40 较为合理.飞灰中的Al和氮化铝(AlN)与水反应生成气体导致胶凝材料产生膨胀,NaOH增加了溶液碱性,促使生成更多的气泡,提高了胶凝材料的膨胀性能;CaCl2 促进了飞灰-水泥胶凝体系的水化反应,生成"云朵"状C—S(A)—H凝胶,凝胶微孔隙中填充簇状水化氯铝酸钙晶体,使得固化体结构更加密实,固化体抗压强度得以提高,同时极大地减小了重金属浸出及二噁英浓度.
Experimental research on the preparation of expansion cementitious materials using municipal solid waste incineration fly ash
In order to realize large-scale resource utilization of municipal solid waste(MSW)incineration fly ash in the field of building materials,the effect of the addition ratio of fly ash,water-solid ratio and addition of admixtures on the performance of fly ash-cement expansion cementitious system was investigated,and the hydration products were analyzed microscopically.The results indicated that with the increasing content of MSW incineration fly ash,the dispersion degree of fly ash-cement slurry decreased,the setting time was prolonged,and the compressive strength decreased continuously.The expansion rate increased first and then decreased and reached maximum when the fly ash content was 60%.As the water-solid ratio of slurry increased,the dispersion degree,the setting time and the expansion rate of fly ash-cement slurry all increased,a more reasonable water-solid ratio between 0.37 and 0.40 should be considered.Al and aluminium nitride(AlN)in fly ash reacted with water to generate gas,leading to expansion of the cementitious material,NaOH increased the alkalinity of the solution,promoting the generation of more bubbles,and improved expansion of cementitious materials.CaCl2 promoted the hydration reaction of the fly ash-cement cementitious system,leading to the formation of"cloud"shaped C—S(A)—H gel,the gel micropores were filled with clusters of hydrated calcium aluminate chloride crystals,making the structure of the solidified body more compact,the compressive strength of the solidified body was improved,and the leaching content of heavy metals and dioxine concentration decreased.

municipal solid waste(MSW)incineration fly ashexpansion cementitious materialsadmixturemicroscopic analysisheavy metal

张元馨、王震、卢前明、刘龙宇、穆月庭、秦华林

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郑州职业技术学院

新疆维吾尔自治区煤炭科学研究所

河南工程学院资源与安全工程学院

生活垃圾 焚烧飞灰 膨胀胶凝材料 外加剂 微观分析 重金属

河南省科技攻关计划新疆维吾尔自治区自然科学基金面上项目河南省高等学校重点科研项目新疆维吾尔自治区公益性科研院所基本科研业务费专项

2321023201132022D01A11622A560020KY2023110

2024

10.12153/j.issn.1674-991X.20230405

环境工程技术学报
中国环境科学研究院

环境工程技术学报

CSTPCD北大核心
影响因子：1
ISSN：1674-991X
年,卷(期)：2024.14(2)
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