The scarcity of suitable coke for use in the blast furnace and the cheapness of natural gas or other fuels can favour the adoption of the direct reduction process for iron production in certain parts of the world and approximately one hundred direct reduction steel plants have been built over the last forty years 用于高炉中的焦炭的稀缺和天燃气及其他燃料低廉的价格使得许多炼铁厂采用直接还原法，在过去的四十多年里有近百家炼铁厂采用此方法。
