direct reduction in rotary kiln

例句：

1. 1. The direct reduction method is a process used to produce iron ore by reducing it with carbon.
   直接还原法是一种通过用碳还原铁矿石来生产铁或的方法。
2. 2. The direct reduction process has been shown to be more efficient than other methods for producing iron ore.
   直接还原过程已被证明比其他方法更高效地生产铁矿石。
3. 3.In the direct reduction process, the iron ore is heated and then reduced in a rotary kiln.
   在直接还原过程中，铁矿石被加热并在回转窑中进行还原。