矿物粒径比引起的岩石微波照射效果差异

微波辅助破岩过程中，影响破岩效果的因素众多，矿物粒径特征是重要的影响因素之一。本文以主要由方解石和黄铁矿组成的岩石为研究对象，根据岩石中矿物实际比例大小，拟定了6种矿物粒径比方案，运用多物理场耦合分析平台COMSOL，建立反映矿物大小比例的分析模型，深入研究了不同方案下微波照射后岩石内部的电磁场、温度场、应力场以及塑性区分布特征和演化规律。研究结果表明：矿物粒径比对微波照射过程中岩石内部电磁场分布规律和量值影响较小。但岩石内部最高温度、温度梯度、第一主应力、最大剪应力均呈增大的变化规律；随矿物粒径比增大，岩石塑性区面积也越大，岩石内塑性区萌生时刻越早，在强吸波矿物内部受拉区面积显著增加，且面积占比越大。总体来看：粒径比越大，岩石内部矿物大小越不均匀，微波照射后岩石弱化程度越高，照射效果越好。

Difference of rock microwave irradiation effect caused by minerals particle size ratio

In the process of microwave assisted rock fragmentation, there are many factors that affect the effect of it, among which the particle size characteristics of minerals are one of the important factors. In this paper, the rock mainly composed of calcite and pyrite is taken as the research object. According to the actual proportion of minerals in the rock, six kinds of mineral particle size ratio schemes are formulated. The multi-physical field coupling analysis platform COMSOL is used to establish an analysis model reflecting the proportion of mineral size. The distribution and evolution of electromagnetic field, temperature field, stress field and plastic zone in rock were studied in depth after microwave irradiation under different schemes. The results show that the mineral particle size ratio has little influence on the distribution and magnitude of electromagnetic field in rock during microwave irradiation. However, the maximum temperature, temperature gradient, first principal stress and maximum shear stress of rock interior all increase in this progress. With the increase of mineral particle size ratio, the area of rock plastic zone increases and the initiation time of it is earlier, the area of tension zone in strong absorbing minerals increases significantly, and the proportion of this area is larger. In general, when the particle size ratio is increase, the mineral size inside the rock is more uneven, meanwhile, the weakening degree of the rock is also higher after microwave irradiation, and the irradiation effect is better.