“废石”怎么读

“废石”的英语可以翻译为：arren rock，mullock ...

随后,他听到她的脚步声离开他, 超过废石砾,渐渐远去.Then he heard her footsteps go away from him, over the rubble.低贫化放矿提高出矿品位,降低废石混入.Low dilution drawing can raise the ore grade of drawing and reduce the mixed waste rock....