DICT.TW Dictionary Taiwan

 Slag n.
 1. The dross, or recrement, of a metal; also, vitrified cinders.
 2. The scoria of a volcano.
 3. Metal. A product of smelting, containing, mostly as silicates, the substances not sought to be produced as matte or metal, and having a lower specific gravity than the latter; -- called also, esp. in iron smelting, cinder. The slag of iron blast furnaces is essentially silicate of calcium, magnesium, and aluminium; that of lead and copper smelting furnaces contains iron.
 Slag furnace, or  Slag hearth Metal., a furnace, or hearth, for extracting lead from slags or poor ore.
 Slag wool, mineral wool. See under Mineral.