coal and coal char

• 煤与煤焦

coal and coal char的用法和样例：

例句

1. With the variation of the ratio of petroleum coke to coal char, the inflexion varies because of the different reactivity between petroleum coke and coal char.
   随石油焦掺入比变化而改变的拐点主要源于石油焦与煤焦的反应性之间差异。