Firstly, this paper used a laser particle size analyzer to test the particle size distribution characteristics of four specific surface areas of phosphate slag powder particles. Then, it used the powder fractal theory to determine the fractal dimension of the different specific surface areas of the phosphate slag powder particle group. Finally, the effect of the fractal dimension of the phosphate slag powder particle group on the mechanical strength and activity index of the phosphate slag powder-cement cementitious system at 3 d, 28 d, and 180 d ages were studied. The results showed that the phosphate slag powder with different specific surface areas has self-similar fractal characteristics; the larger the specific surface area of phosphate slag powder, the higher the fractal dimension, and the fractal dimension of phosphate slag powder particle can characterize the properties of phosphate slag powder’s fineness and particle gradation in the process of grinding and refining. The phosphorus slag powder particle fractal dimension, the mechanical strength, and activity index of the phosphorus slag powder-cement cementitious system have linear correlation characteristics; the larger the fractal dimension, the higher the mechanical strength and activity index of the cementitious system with phosphate slag powder.

首先，利用激光粒度分析仪测试了磷矿渣粉颗粒四种比表面积的粒度分布特征。然后，利用粉体分形理论确定了磷矿渣粉体颗粒群不同比表面积的分形维数。最后研究了磷酸矿渣粉颗粒群的分形维数对磷酸矿渣粉-水泥胶凝体系3 d、28 d、180 d龄期机械强度和活性指数的影响。结果表明，不同比表面积的磷矿渣粉具有自相似的分形特征；磷酸盐渣粉的比表面积越大，其分形维数越高，磷酸盐渣粉颗粒的分形维数可以表征磷酸盐渣粉在磨细过程中的细度和颗粒级配的性质。磷渣粉-水泥胶凝体系的磷渣粉颗粒分形维数、机械强度和活性指数均具有线性相关特征；分形维数越大，磷酸盐矿渣粉胶凝体系的机械强度和活性指数越高。