ingot grinding

例句：

1. 1.The forge is the heart of the blacksmith's workshop.
   锻炉是铁匠工作室的核心。
2. 2. The smelter uses coal to produce iron.
   熔炼厂使用煤炭生产铁。
3. 3. The blacksmith was hard at work in his forge all day long.
   铁匠整天在锻炉里辛勤工作。