机械力对柠檬酸改性磷石膏颗粒粒径与微观结构的影响

The Influence of Mechanical Force on the Particle Size and Microstructure of Citric Acid Modified Phosphogypsum Particles

摘要: 本文研究了机械研磨对柠檬酸预处理磷石膏颗粒的细化作用与结构演变规律。通过对不同研磨时间(0 min~50 min)下样品的粒度分布、微观形貌及表面化学状态进行系统表征，发现研磨可显著促进颗粒破碎与均匀化，20 min后中位粒径显著下降，10 μm~30 μm区间颗粒成为主导。RRB与Swebrec模型均能有效描述粒度分布特征，其中RRB模型拟合优度更高(R² > 0.990)。扫描电镜显示研磨后颗粒由规则片状转变为粗糙多级结构，暴露出更多活性表面；红外光谱与XPS分析表明，机械力破坏了二水石膏晶体结构，诱导表面生成非晶态磷酸氢钙，显著提升了磷石膏的化学活性。研究结果为磷石膏的机械活化工艺优化提供了理论依据。

Abstract: This article investigates the refining effect and structural evolution of citric acid pretreated phosphogypsum particles by mechanical grinding. By systematically characterizing the particle size distribution, microstructure, and surface chemical state of samples at different grinding times (0 min~50 min), it was found that grinding can significantly promote particle fragmentation and homogenization. After 20 min, the median particle size significantly decreased, and particles in the 10 μm~30 μm range became dominant. Both RRB and Swebrec models can effectively describe the characteristics of particle size distribution, with the RRB model having a higher goodness of fit (R² > 0.990). Scanning electron microscopy showed that after grinding, the particles transformed from regular flakes to rough multi-level structures, exposing more active surfaces; Infrared spectroscopy and XPS analysis indicate that mechanical force destroys the crystal structure of dihydrate gypsum, induces the formation of amorphous calcium hydrogen phosphate on the surface, and significantly enhances the chemical activity of phosphogypsum. The research results provide a theoretical basis for optimizing the mechanical activation process of phosphogypsum.