炉子

例句：

1. 1.The furnace is heating up the metal tobe smelted.
   熔炉正在加热金属以进行冶炼。
2. 2. Theblacksmith was using aforge to shape iron.
   铁匠正在使用火炉来塑造铁。
3. 3. The furnace was producing high-qualitysteel.
   熔炉生产出高质量的钢材。