Abstract: The study aims to reveal the internal relationship between the particle size and the degree of dissociation of high-voltage electro-pulsed crushing products and construct a dissociation model that conforms to its crushing mechanism.Tak ing the Zijinshan copper ore as the research object,two crushing methods,namely high-voltage electro-pulsed crushing and cen trifugal impact crushing,were used to crush the ore to a similar particle size distribution.The Mineral Liberation Analyzer (MLA) was employed to test and analyze the distribution of pyrite,the main metallic mineral,and quartz,the main gangue mineral,in the crushed products.With the aid of the extended Gaudin model,the dissociation distributions of the two crushing methods were fitted,and the selective dissociation capabilities of the two methods for pyrite were quantitatively compared through the grain boundary fracture factor P value.The MLA test results show that within the particle size range of 0.075 to 1.7 mm,the proportion of completely dissociated pyrite in the products of high-voltage electro-pulsed crushing is significantly higher than that in the products of centrifugal impact crushing.In contrast,there is no significant difference in the proportion of completely dissociated quartz between the two crushing methods.The extended Gaudin model exhibits a good fitting effect on the particle size distribution of completely dissociated pyrite in the products of both crushing methods,with the coefficient of determination (R²) ranging from 0.95 to 0.99.Further analysis of the fitted P values shows that the P value of high-voltage e lectro-pulsed crushing is 0.42,while that of centrifugal impact crushing is 0.24,indicating that high-voltage electro-pulsed crushing has a more prominent advantage in selective dissociation.The extended Gaudin model can well fit the dissociation distribution of pyrite under the two crushing methods,providing an effective model tool for studying the crushing mechanism of high-voltage electro-pulsed crushing and optimizing mineral processing techniques.