微波加热路径对硬岩破碎效果影响试验研究

 不同的微波加热方式会对岩石产生不同的加热效果，功率和时间是影响破岩效果的2个重要参数。对立方体和标准圆柱形玄武岩试样进行了3种加热路径下的微波辐射试验，并对辐射前后的试样进行P波波速和单轴压缩强度测试。结果表明，当试样内产生的热应力先超过岩石的强度极限时，试样就会崩开破坏；当试样温度先达到岩石熔点时，试样以熔化为主。采用高功率微波连续加热岩石，试样在较短时间、较低温度就发生崩开破坏，试样在崩开前波速和单轴压缩强度发生了显著降低，且功率越高，试样崩开的时间越短，波速和强度折减的越快。因此，采用高功率微波连续辐射岩石，借助于其产生的热应力使岩石崩开破碎的特点，可显著降低岩石破碎时的能量消耗，这对于微波单独应用于开采中的破碎工艺及辅助机械破岩掘进等具有重要意义。

The influence of heating path on the effect of hard rock fragmentation using microwave assisted method

Different heating paths produce the different heating effects. The power and the heating time are the important parameters influencing the rock fragmentation. The microwave heating tests were conducted to the cubic and cylindrical basalt samples under three different heating paths and the P-wave velocity and UCS were measured before and after the microwave treatment. The sample burst into fragments when the thermal stress within the sample exceeds the ultimate strength of the rock. The sample was largely melt when the temperature in the sample exceeded the melting point. When a high microwave power was applied，the sample burst into fragments in shorter time and consumed low energy. The P-wave velocity and UCS had a significant reduction before the sample burst. The higher the power，the shorter the burst time and the faster the strength reduction. Therefore，the high power microwave can be used in rock fragmentation or assisted mechanical rock breakage with significantly decrease in energy consumption.