以宁夏银北地区典型盐碱土壤为研究对象，采用X射线衍射(XRD)、红外光谱(FTIR)、比表面全自动物理吸附仪(BET)以及扫描电子显微镜(SEM)等测试技术对粉煤灰基土壤调理剂作用下盐碱土壤颗粒微观结构进行研究和系统表征。结果表明，利用调理剂改良后土壤矿物的主要成分未发生改变，但是添加调理剂后土壤有新晶相方解石生成；土壤的pH值大幅降低，由9.01降低到7.66；土壤红外吸收变化较小，Si-O-Si和有机质吸收峰略有增强；随着调理剂的增加，土壤小颗粒开始团聚，孔隙率逐渐增加，以添加2.5wt%组为例，15天后样品孔隙率达到21.30%，30天后样品孔隙率达到25.29%，约为未添加调理剂组的两倍；土壤颗粒的比表面积略有增加，30天后由初始的23.06 m2/g增加到25.55 m2/g。

The field test results have shown that the physical and chemical properties of saline-alkali soil can be significantly improved by adding fly ash-based soil conditioner. However, at present, the improving mechanism of fly ash-based soil conditioner is not clear, and the structural change law of soil particles is not understood. So this work took the typical saline-alkali soil in the Yinbei area of Ningxia Hui Autonomous Region as the research object, studying the microstructure of saline-alkali soil particles under the action of fly ash-based soil conditioner by X-ray diffraction (XRD), infrared spectroscopy (FTIR), specific surface automatic physical adsorption instrument (BET) and scanning electron microscope (SEM). The results showed that the main components of soil minerals did not change, but a new crystal phase calcite was found in the soil after the fly ash-based soil conditioner was added and the pH value of the soil was greatly reduced from 9.01 to 7.66. The infrared absorption of the soil with fly ash-based soil conditioner changed little, but the absorption peaks of Si-O-Si and organic matters were slightly enhanced. The soil microstructure changed greatly with the increase of the conditioner addition since the small soil particles began to aggregate and the soil porosity gradually increased. Taking the 2.5wt% group as an example, its porosity was up to a level of 21.30% after 15 days and 25.29% after 30 days, which was about twice that of the blank control group. The specific surface area of soil particles increased slightly from the initial value of 23.06 m2/g to 25.55 m2/g after 30 days. The above results proved that fly ash-based soil conditioner could not only alleviate the problem of land salinization, but also realized the large-scale consumption of fly ash solid waste.