Making-Iron Technology制铁技术
shaft furnace making sponge iron竖炉海绵铁法
retort process making sponge iron反应罐法
steel making iron炼钢生铁
making iron splines铁样制作
machinery for making iron炼铁机械
Burning coke in steel-making iron烧焦炭炼钢铁
Blast furnace iron making高炉炼铁