煅烧

例句：

1. 1.The coal was heated to a high temperature before it could be used.
   煤在被使用之前需要加热到高温。
2. 2.The iron ore was melted down to extract the valuable metals.
   铁矿石被熔化以提取有价值的金属。
3. 3. The pottery was carefully fired at high temperatures to achieve its desired hardness.
   陶器在高温下被仔细烧制，以达到所需的硬度。