Slag from British steel work

[Porcy Mane]

Previous to that, it was just tipped onto slag banks by short trains of what were termed slag ladles.

 

The periodic orange glow in the skies above our town, when this was done, led to the motto beneath our coat of arms, "Refulget labores nostros coelum" (The heavens reflect our labours).

 Sort of like this.

 

https://britainfromabove.org.uk/en/image/EAW050695

 

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[meil]

Slag from Cyfarthfa steelworks

May be but you said it was from a blast furnace. Blast furnaces produce iron not steel. And your picture is of Blast Furnace slag not steel slag.

Edited March 10, 2018 by meil

[Arthur]

 

 

One of these is blast furnace (iron)slag, the other basic oxygen converter (steel) slag.

 

 

 

 

 

 

There is little visual difference.

 

 

Iron slag is produced during a process of chemical reduction, steel slag in an oxidising process. However, both have similar chemical compositions.

Both contain around 45 % limestone (it being the flux in both processes) silicates and magnesium oxide such that, typically, they are around 65% the same.

 

Iron slag has sulphur picked up from the smelting fuel, coke.

 

Steel slag contains iron oxide and phosphorous oxides. Phosphorous is present in most ores and is not removed in the blast furnace. It must be eliminated from steel and it’s presence caused Henry Bessemer a lot of problems.

 

 

Slags can have different appearances but the biggest determining factors are how the slag is cooled and what processing it has undergone.

 

Has it been dry or water cooled, how quickly was it cooled, has it been aerated or foamed, blown into fibre strands, has it just been tipped, was it tipped as a liquid or a solid and how long has it been weathering for? Has it been crushed and graded?

 

All of these factors have a much greater influence on the appearance of slag than whether it originated in an iron or steel making furnace.