free-ash coke

例句：

1. 1.The factory uses free-ash coke to produce electricity.
   这家工厂使用自由灰煤来发电。
2. 2.Free-ash coke is a popular fuel for industrial processes.
   自由灰煤是工业过程中常用的燃料。
3. 3. The use of free-ash coke has been banned in some areas due to air pollution concerns.
   由于空气污染问题，某些地区已经禁止使用自由灰煤。