The microwave high-temperature irradiation was introduced to deal with the low efficiency of traditional microwave treatments for breaking granite. Structural evolution of granite between 300 °C and 800 °C was assessed through the morphology, mineral characteristics and mechanical performance. A spherical melt cavity with radial cracks formed near the biotite-rich area at 600 °C and the rock completely disintegrated at 800 °C. Intergranular crack was the main mode of micro-cracks. Besides, the micro crack propagation at 600 °C was affected by the distribution and shapes of mineral grains and original cracks. Furthermore, the intergranular crack in the biotite grain boundary induced many secondary smaller cracks. Feldspar and biotite melted at 800 °C. Thus, the melt probably initiated from the cracked-intensive feldspar near biotite-rich area. The uniaxial compressive strength of granite decreased from 88.17 MPa at 25 °C to 18.61 MPa at 800 °C. Between 300 and 600 °C, the decrease in the uniaxial compressive strength was associated with moisture releasing, quartz transition and thermal induced cracks, and 600–800 °C, the decrease was mainly contributed by the partial melt of rock, and magma intruding and solidifying.

中文翻译：

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微波辐射诱导高温下花岗岩结构演化的实验研究

引入微波高温辐照来解决传统微波处理破碎花岗岩效率低的问题。通过形态、矿物特征和机械性能评估花岗岩在 300°C 和 800°C 之间的结构演变。600°C 时在富含黑云母的区域附近形成带有径向裂纹的球形熔体腔，800°C 时岩石完全崩解。晶间裂纹是微裂纹的主要形式。此外，600 ℃时的微裂纹扩展受矿物颗粒和原始裂纹的分布和形状的影响。此外，黑云母晶界的晶间裂纹诱发了许多次生较小的裂纹。长石和黑云母在 800 °C 下熔化。因此，熔体可能起源于富含黑云母的区域附近的裂化密集长石。花岗岩的单轴抗压强度从25℃时的88.17 MPa下降到800℃时的18.61 MPa。300～600℃，单轴抗压强度的降低与放湿、石英转变和热致裂纹有关，600～800℃，降低主要由岩石部分熔融、岩浆侵入和凝。