Particle size effects and Weibull statistical characterization of fracture behavior in multi-component phosphate ore

In this study, uniaxial compression tests were conducted on quartz, dolomite, apatite, and phosphate ore to analyze the fracturing behavior of pure minerals and actual ores under different particle size conditions. The fracturing characteristics were characterized using the Weibull distribution model. Experimental results indicate that for pure mineral specimens, the distributions of σ0 and m are relatively concentrated, and their fracturing behavior is relatively regular, primarily governed by the intrinsic mechanical properties of the minerals. In contrast, due to the influence of multi-mineral distribution, mineral interfaces, and structural defects, the distributions of σ0 and m in actual ores exhibit more pronounced dispersion, and their fracturing behavior gradually deviates from the characteristics typically observed in single-mineral specimens. As particle size increases, structural heterogeneity in actual ore gradually becomes the dominant factor, manifesting as a decrease in characteristic strength and Weibull modulus, as well as increased variability in crushing behavior; this scale effect is relatively weak in pure minerals. Studies indicate that σ0 and m are not fixed material constants, but rather statistical parameters that evolve with changes in particle size. These findings provide experimental support for modeling the crushing and grinding processes of multi-component ores and for the scale correction of strength parameters.