高掺量磷石膏人造骨料内部微结构特征研究

Study on the Microstructure Characteristics of Artificial Aggregate with High Content of Phosphogypsum

以质量百分比80%以上的磷石膏和少量矿渣、水泥等胶凝材料制备了一种新型人造骨料。利用光学显微镜、电子探针以及扫描电镜等测试手段针对不同暴露环境下龄期达1年的磷石膏人造骨料中石膏颗粒、水化产物形态和微结构等进行了分析测试。研究表明,骨料内部石膏颗粒呈现出以长条状颗粒形状为主的交错紧密堆积形态,占据骨料大部分空间;大小不等的孔洞分布于骨料内部;骨料硬化体主要依靠石膏颗粒之间的少量水化产物实现粘结;人造骨料微结构和性能受到暴露环境条件的影响。

A new type of artificial aggregate was prepared with more than 80%weight percentage of phosphogypsum and a small amount of slags,cements and other cementing materials.Optical microscope,electron probe and scanning electron microscope were used to analyze the morphology and microstructure of gypsum particles and hydration products in phosphogypsum artificial aggregates aged more than one year in different exposure environments.The results show that the gypsum particles in the aggregate are mainly in the shape of long strip particles,which are staggered and closely stacked and occupy most of the interior space of the aggregate;the micropores of different sizes are distributed in the aggregate;the hardened aggregates are bonding mainly by a small amount of hydration products between the gypsum particles.The microstructure and properties of artificial aggregate are affected by the environmental conditions.