the act or process of getting a metal from rock by heating it to a very high temperature, or of melting objects made from metal in order to use the metal to make something new

Iron mining and smelting reached their peak during the second half of the nineteenth century. 铁矿开采和冶炼在十九世纪下半叶达到顶峰。

The mining and smelting released lead and other dangerous metals into the river basin. 采矿和冶炼将铅和其他危险金属释放到河流流域。