Fractal research on the particle size distribution and activity index of iron ore tailings powder

To study the effect of particle size distribution on reactivity of iron ore tailings( IOT),four different particle size distribution of IOT were tested,and its fractal dimension was also calculated by the fractal theory.Relationships among the particle size distributional fractal dimension and average particle size,specific surface area,compressive strengths of mortars and activity index were analyzed. The results suggested that positive linear correlation index was obtained between the particle size distributional fractal dimension and specific surface area of the IOT,and the activity index of mortars of which the correlation index were 0. 974 4 and 0.969 5,respectively. In addition,negative linear correlation index was obtained between the particle size distributional fractal dimension and average particle size( D50) and D90. The correlation indexes were-0.995 2 and-0.931 7,respectively. The fractal dimension has much more significant effect on the 28 d compressive strength of mortars than that of 3 d,with different correlation index of 0.982 9 and 0.951 8,respectively.