Thermal Effect And Thermodynamic Response Characteristics Of Water-bearing Rock Under Microwave Irradiation

In order to overcome the shortcomings of traditional drilling and blasting methods and mechanical rock breaking methods,improve hard rock breaking efficiency and reduce energy consumption,in recent years,clean,green and efficient microwave technology has become a research hotspot for new rock breaking methods.Water is a good waveabsorbing medium and can improve the microwave absorption capacity of rocks.In this paper,laboratory experiments are carried out by means of infrared thermal imaging temperature measurement technology,nuclear magnetic resonance spectroscopy detection technology and SHPB dynamic impact test.From macroscopic and mesoscopic levels,different water saturation on the microwave irradiation effect of basalt and granite was studied.The main research contents are as follows:(1)By irradiating Φ50*25mm basalt with different water saturation with microwave,with the help of infrared thermal imaging equipment and processing software,the average temperature and temperature gradient distribution data on the surface of the sample during the irradiation process were obtained.The heating process and temperature gradient change law of the sample were analyzed,and the mechanism of microwave-induced fracture of hydrous basalt was discussed.(2)Through ultrasonic velocity test and nuclear magnetic resonance test of Φ50*25mm basalt and granite samples with different water saturation before and after microwave irradiation,and the pore structure change characteristics of the two rocks after microwave irradiation and the effect of water saturation on microstructure damage were obtained.(3)Dynamic splitting tests were carried out on two samples ofΦ50*25mm after microwave treatment,and uniaxial compression tests were performed on granite samples of Φ50*100mm,and the strength reduction characteristics of the two rock samples under different water saturation were analyzed.It is concluded that link between the water saturation by affecting the internal temperature field of the rock,leading to the occurrence of microscopic damage and ultimately affecting the macroscopic strength.Figure:58,table:20,references:128...