Slag (?), n. (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, v. i. & t. [imp. & p.
p. Slagged (?); p. pr. & vb. n.
Slagging.] (Metal.) To form, or form into, a slag;
to agglomerate when heated below the fusion point.
Slag (?), n. [Sw. slagg, or LG.
slacke, whence G. schlacke; originally, perhaps, the
splinters struck off from the metal by hammering. See Slay,
v. t.] 1. The dross, or
recrement, of a metal; also, vitrified cinders.
2. The scoria of a volcano.
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.