coal preparation process

例句：

1. 1.The coal preparation process involves a series of steps to extract coal from the earth.
   煤炭准备过程涉及一系列步骤，从地下提取煤炭。
2. 2. The coal preparation process is crucial for power generation and industrial production.
   煤炭准备过程对于发电和工业生产至关重要。
3. 3. The coal preparation process has improved significantly in recent years due to technological advancements.
   由于技术进步，煤炭准备过程在近年来有了显著的改进。