The refuse or dross thrown off from iron or other metals in the furnace; scoria, slag. (Usually in singular) Now technical.

The scum, recrement, or extraneous matter thrown off from metals in the process of melting.

The slag or dross remaining after the smelting out of a metal from its ore. Also transferred.

Dross which rises to the surface in the purifying of a metal; refuse, slag. Obsolete.

(See quot. 1607.)

spec. The slag or dross separated from a metal during smelting. In later use in figurative context. Now rare.

Stony waste material separated from metals during the smelting or refining of metal, and resulting from the reaction of a flux (flux, n. 11) such…

= scoria, n.

A form of slag.

a dark brown or black solid produced as a by-product of smelting iron (later identified as magnetite).

In lead smelting: partially smelted ore, or a mixture of this with heated fuel.

cinders, iron flakes, and other waste material from a forge.

A molten mixture of impure metal sulphides or oxides produced during the smelting of certain ores of copper, nickel, etc.

Founding. Metal scoria or slag.

(see quot.).

Having the base in excess. slag from the basic or Bessemer process of steel manufacture, used as a fertilizer when finely ground.