磷石膏颗粒级配、结构与性能研究

Study on the Grading, Microstructure and Property of Phosphogypsum

磷石膏的颗粒级配、结构是影响性能的重要因素。采用筛分、沉降天平分析、SEM显微结构分析 ,研究了磷石膏颗粒级配与二水石膏晶体形貌 ,测定了不同形态磷与有机物等杂质在磷石膏中分布。分析、测试了磷石膏胶结材的结构与性能。结果表明 :磷石膏的颗粒级配、形貌与天然石膏存在明显差异 ,它的颗粒级配成正态分布 ,二水石膏晶体粗大、均匀 ,以板状为主 ,其尺度比天然二水石膏晶体粗大。可溶磷与有机物覆盖于二水石膏晶体表面 ,其含量随磷石膏粒度增加而增加。粉磨使磷石膏颗粒形貌多样化 ,并改善颗粒级配 ,降低其胶结材需水量 ,使硬化体结构趋于密实 ,强度得以提高。磷石膏经过中和。

The grading and constitution of phosphogypsum are main factors affecting its properties. By means of dressing by screen, sedimentation balance, SEM, the grading and the crystal morphology of phosphogypsum were studied. The distribution of different forms P 2O 5 and organic matter was measured. The microstructure and properties of phosphogypsum binder were analyzed and measured. Experimental results show: the grading and morphology of phosphogypsum differ obviously from natural gypsum's. Its grading display normal distribution, gypsum crystals display hexahedron with thickness and uniform, bigger than size of gypsum. Water soluble P 2O 5 and organic matter are distributed on surface of dihydrte gypsum crystals, and their contents increase with increasing of phosphogypsum size. Powering improves grading, makes the morphology various and reduces the water demand of binder, makes structure of hardened body become compact and strength increase. High class calined gypsum can be made by phosphogypsum neutralized and powered.