Slag

Slag is an industrial byproduct from various industries, including coke, coal, glass making, and metal smelting.

It can be found all over the UK – it was used as filler for railway tracks and embankments, and can also be found about areas of historical industry.

Appearance, Uses and History

I’ve written quite a lengthy article on slag here; there is no sense in me posting the same information again! 🙂

Slag often looks like a black volcanic rock similar to scoria, but can be glassy and multicoloured too! It is purely an industrial byproduct but can be interesting or attractive.

Locales

Anywhere with a history of industry. 90% of the UK and probably most of the rest of the world.

Mineralogy

Chemistry
Would drastically vary based on the type of slag.
Colours and Variations
Typically grey to black, sometimes partially iridescent. When comprised of glass, it could be any colour.
Streak
Luster
Dull to glassy.
Fracture
Transparency
Usually opaque, sometimes translucent.
Crystal habit
N/A.
Mohs hardness
Varies based on composition.
Specific Gravity
Varies based on composition.
Fluorescence
Varies based on composition.
Easiest testing method
Common Treatments
None.

Hazards and Warnings

Almost all rocks, minerals (and, frankly, almost all other substances on earth) can produce toxic dust when cutting, which can cause serious respiratory conditions including silicosis.

When cutting or polishing rocks, minerals, shells, etc, all work should be done wet to minimise the dust, and a suitable respirator or extraction system should be used.

Translations

Slag and clinker may not translate well into other languages. If you know of more appropriate words please let me know!

Arabic:

  • الكلنكر

Hindi:

  • धातुमल

Portuguese:

  • escória
  • clínquer

Bengali:

  • স্ল্যাগ

Indonesian:

Punjabi:

English:

  • slag
  • clinker
  • slaggy waste material
  • dross

Italian:

  • scorie

Russian:

  • шлак

French:

  • scories
  • mâchefer

Japanese:

  • スラグ
  • クリンカー

Spanish:

  • escoria

German:

  • Schlacke

Korean:

  • 광재

Thai:

  • ปูนเม็ด

Gujurati:

Mandarin and Traditional Chinese:

  • 矿渣
  • 熟料
  • 礦渣

Urdu:

  • کلینکر

Further Reading / External Links