Research On Mechanical Structure Effect Of Particle Fracture Of Micro-disseminated Gold Or

Micro-disseminated gold ore particles have the characteristics of difficult crushing and complex morphology structure,which makes the beneficiation process still face the problems of huge energy consumption and low efficiency.Therefore,this paper is based on the National Natural Science Foundation of China(51774101)"Research on the macro-micro mechanical behavior and structure effect of three-dimensional rock particle fracture″.Taking No.30 middle section of Lannigou Gold Mine as the research background,theoretical analysis,physical test,and numerical analysis are comprehensively used.The fracture evolution mechanism and acoustic emission behavior characteristics of ore particles with different sizes and structures were analyzed,and the single-particle and multi-particle ore rocks were simulated by RFPA-CT.The main conclusions are as follows:(1)The compressive strength of ore-rock particles decreases exponentially with the increase of particle size.The peak strength is more discrete when the particle size is greater than 50 mm.The peak strength has medium anisotropy.The effective elastic modulus of initiation strength is the largest.The closure strength is the second,and the peak strength is the smallest.(2)A dent near the contact between the particles and the loading plate during loading.The energy released by the samples without filling structure and the samples with calcite filling structure in the compaction stage are less.The failure mode of specimens without filling structure is mainly tensile failure.The main failure mode of calcite filling is a mixed failure.The artificial cutting structure samples are a mainly split failure.(3)During the fracture process,a large number of shear failure elements are generated near the end of the specimen with a small contact area with the loading plate.Meanwhile,a large number of microcracks are produced.The linear behavior of the force-displacement curve of unfilled structure occurs longest.The linear behavior of the force-displacement curve of the artificial cutting structure is short.It is also found that the number of damaged elements after peak strength is not related to the internal filling structure of the specimen.The failure of the specimen is caused by the joint coalescence of one or more sets of cracks,leading to the instability and failure of sandstone.(4)The fracture of multi-particle specimens during compression is not the peak stress point.It appears after the peak stress point.Large particles break into small ones during the rupture.And the particles rolling re-arranged,resulting in the reduction of void space,resulting in smaller changes in normal displacement.The above research finally provides a reference for the crushing of finely disseminated gold ore particles.