基于微波加热技术的硬岩破裂方法探究
Research on the method of hard rock cracking based on microwave heating technology
-
摘要: 硬岩的破裂问题一直是岩土工程界普遍关注的热点。硬岩因具有很高的硬度和强度参数,机械类破岩(TBM掘进、矿石破碎)过程中的刀具严重磨损和超高能耗一直是制约其在硬岩中应用的突出问题。若能通过合理技术实现硬岩的初步裂化,有效降低硬岩的物理力学参数,将为机械类破岩技术在硬岩中的广泛应用提供前提条件。然而,当前研究的几种辅助破岩方法存在着破岩体积小等不足。微波照射技术作为辅助破岩的手段之一,能够一定程度上实现岩石的初步裂化。基于微波照射下的岩石裂化现象,首先系统分析了微波照射的内在作用机制,以及在辅助围岩预裂和矿石破碎方面的国内外已有研究成果;然后,总结并提出了微波辅助破岩有待完善之处;最后基于常见的高硬度材料-花岗岩与磁铁矿石的微波加热试验,在微波加热对花岗岩的破裂特性方面,研究了岩石围压和微波加热路径对花岗岩强度影响的优先级顺序,并由此提出了使用“水压致裂+微波照射”组合方式来破裂地下深部侧限围压约束下的花岗岩。在微波加热对提高矿石破碎效果方面,探究了在不同微波加热方式下的含层理矿石与无层理磁铁矿石的力学性能,以及微波冷却路径对提高矿石破碎程度的潜在价值。研究成果为微波加热技术在硬岩破碎领域的进一步应用提供了参考。Abstract: The fracture of hard rock has always been the focus of geotechnical engineering.Due to the high hardness and strength of hard rock, severe tool wear and high energy consumption in the process of mechanical rock fracture(TBM tunneling and ore comminution) have always been the main problems restricting its application in hard rock.If the initial cracking of hard rock can be realized using some rational technologies and the physical mechanical parameters of hard rock can be effectively improved, it will provide a prerequisite for the wide application of mechanical rock fracture technology in hard rock.However, the current methods that assist rock fracture have some shortcomings such as small rock crashing volume.As one of the auxiliary rock fracture methods, microwave irradiation technology can realize the initial rock crashing.Based on the phenomenon of rock cracking under microwave irradiation, this study first analyzes the internal mechanism of microwave irradiation, microwave-assisted surrounding rock pre-cracked and microwave-assisted ore comminution at home and abroad, and then puts forward the improvements of microwave-assisted rock fracture.Finally, based on the microwave heating test of common high hardness materials-granite and magnetite ore, in terms of the fracture characteristics of microwave heating on granite, the priority order of the influence of rock confining pressure and microwave heating path on the strength of granite is studied, and the combination of “hydraulic fracturing + microwave irradiation” is proposed to fracture the granite under the constraint of lateral confining pressure in deep underground.In terms of the effect of microwave heating on ore crushing, the mechanical properties of layered magnetite ore and non-layered ore under different microwave heating methods and the potential value of microwave cooling path on improving the degree of ore crushing are investigated.The research results provide reference for the further application of microwave heating technology in the field of hard rock fracture.
下载: