Dross vs. Slag — What's the Difference?

Dross is a mass of solid impurities floating on a molten metal or dispersed in the metal, such as in wrought iron. It forms on the surface of low-melting-point metals such as tin, lead, zinc or aluminium or alloys by oxidation of the metal.

Slag is the glass-like by-product left over after a desired metal has been separated (i.e., smelted) from its raw ore. Slag is usually a mixture of metal oxides and silicon dioxide.

Waste or impure matter

The vitreous mass left as a residue by the smelting of metallic ore.

The scum that forms on the surface of molten metal as a result of oxidation.

See scoria.

Worthless, commonplace, or trivial matter

To change into or form slag.

Waste or impure matter.

Waste material from a mine.

Residue that forms on the surface of molten metal from oxidation.

Scum that forms on the surface of molten metal.

The impurities in metal.

Impurities formed and separated out when a metal is smelted from ore; vitrified cinders.

A waste product from working with metal.

Hard aggregate remaining as a residue from blast furnaces, sometimes used as a surfacing material.

(figurative) Worthless or trivial matter.

Scoria associated with a volcano.

(transitive) To remove dross from.

A coward.

The scum or refuse matter which is thrown off, or falls from, metals in smelting the ore, or in the process of melting; recrement.

A contemptible person, a scumbag.

Rust of metals.

A prostitute, or a woman who acts like one; a slut.

Waste matter; any worthless matter separated from the better part; leavings; dregs; refuse.

(transitive) To produce slag.

Worthless material that should be removed;

(intransitive) To become slag; to agglomerate when heated below the fusion point.

The scum formed by oxidation at the surface of molten metals

(transitive) To reduce to slag.

To talk badly about; to malign or denigrate (someone).

To spit.

The dross, or recrement, of a metal; also, vitrified cinders.

The scoria of a volcano.

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.

To form, or form into, a slag; to agglomerate when heated below the fusion point.

The scum formed by oxidation at the surface of molten metals