Institute of Resources and Environmental Engineering,Shanxi University
State Environmental Protection KeyLaboratory on Efficient Resource-utilization Techniques of Coal Waste,Shanxi University
School of Electricity and Architecture,Shanxi University

由于传统硅酸盐水泥基建材生产过程排放大量CO2,近几年以地质聚合物(地聚物)为代表的新型低碳胶凝材料成为研究热点。作为我国大宗工业固体废弃物,粉煤灰富含硅铝酸盐,通过碱激发制备地聚物可实现粉煤灰大宗消纳。综合论述了粉煤灰的碱激发反应活性评估方法,总结了粉煤灰碱激发反应机理,归纳了粉煤灰类型、激发剂、原料配比和养护制度等关键因素对地聚物形成和性能的影响规律,提出了目前研究存在的问题,并从粉煤灰活性组分评估和碱激发体系元素组成的角度,对未来研究方向进行展望。粉煤灰的反应活性评价方法主要有Rietveld全谱图拟合法、饱和石灰溶液吸收法和酸碱溶出法。粉煤灰碱激发反应过程可分为解构—重构—凝聚—聚合4个阶段,解构过程中溶出的硅铝比(Si/Al物质的量比)对凝胶结构和材料力学性能有重要影响,不同研究获得的最佳Si/Al物质的量比存在较大差异。目前关于原料配比、养护制度和凝胶结构等因素对地聚物性能影响研究获得的变化规律并不一致,为粉煤灰碱激发反应机理和地聚物合成研究带来困难,未来应针对不同类别粉煤灰理化特性,建立碱激发体系各元素配比统一的计算方法,为粉煤灰基地聚物合成时统一设计标准奠定理论基础。

Due to the large amount of CO2 emitted from the production process of traditional portland cement-based building materials, thenew low-carbon cementing materials represented by geopolymer have become a research hotspot in recent years. Fly ash, as a bulk industrial solid waste in China, is rich in aluminosilicates, and the preparation of geopolymer by alkali - activated method can realize thebulk consumption of fly ash. In this paper, the evaluation method of alkali-activated reactivity of fly ash was discussed, the reaction mechanism of fly ash and alkali activator was summarized, the effects of key factors such as fly ash type, activator, raw material ratio and curing system on the properties of geopolymers were summarized, and the existing problems in current research were proposed, and the future research directions from the perspective of evaluation of active components of fly ash and elemental composition of alkali activationsystem were prospected. The reactivity evaluation methods of fly ash mainly include Rietveld full spectrum fitting method, saturated limesolution absorption method and acid-base dissolution method. The reaction process of alkali-activated fly ash can be divided into four stages: dissolution, gelation, condensation and polymerization. The dissolved Si/ Al molar ration from fly ash in the process of decompositionhas an important influence on the gel structure and mechanical properties of geopolymer, and the optimal Si/ Al molar ration obtained bydifferent studies has a great difference. The effects of raw material ratio, curing system, gel structure and other factors on the propertiesof geopolymer obtained by different studies has a great difference, which brings difficulties to the research on the mechanism of fly ash alkali excitation reaction and the synthesis of geopolymer. In the future, a unified calculation method for the proportion of elements in alkaliactivated fly ash should be established according to the physical and chemical properties of different types of fly ash, laying a theoreticalfoundation for the unified design standard of fly ash-based geopolymer synthesis.

国家自然科学基金资助项目(22078181);山西省青年基金资助项目(201901D211178)

孙浩,马志斌,路广军,等.粉煤灰碱激发制备地质聚合物研究进展[J].洁净煤技术,2023,29(11):140-153.

SUN Hao,MA Zhibin,LU Guangjun,et al.Review on geopolymer preparation by alkali activation of coal fly ash[J].CleanCoal Technology,2023,29(11):140-153.