Experimental Study on Acoustic Characteristics of Particle Breakage Under Combined Shear and Extrusion Load

Abstract

The jaw crushing loading process is a typical loading process of combined shearing and extrusion. In this paper, by establishing a complete jaw crushing loading process, the sonic test method is used to determine and analyze the particle crushing law to explore acoustic characteristics of particle crushing under the combined action of shear and extrusion. A jaw crushing tester is used to simulate the jaw crushing process of sand aggregate specimens. A rock-soil sound wave detector is used to measure the sound speed, sound amplitude, and sound intensity during the simulated jaw crushing process. It is found that when the jaw angle variation range is 2.6°, the inlet-outlet ratio is 0.332 and the motor speed is 15 r/min, the sound velocity and the sound amplitude curves fluctuate more drastically and the sound intensity is higher. The crushing evaluation of the sand aggregate specimens, which have experienced crushing simulation, shows that when the jaw angle variation range is 3.0°, the inlet-outlet ratio is 0.332 and the motor speed is 33 r/min, higher crushing energy rate and crushing rate are achieved. Through the comparative analysis of each group’s acoustic parameters and crushing evaluations, it is found that both the acoustic parameters and the crushing evaluations reflect the crushing process, but they have similarities and differences. Therefore, to some extent, the acoustic parameters in the crushing process can be regarded as significant indicators for evaluating the crushing effect. This conclusion may be a reference for optimizing working parameters and structural parameters of crushing equipment.