Due to the very fluid slag, care must be taken to ensure that the work is free of rust, heavy mill scale and paint.

The upper fill was a very fine and loose black layer, dominated by plant impressed fluid slag and two large slag pieces.

During the steelmaking process, the gangue in DRI is removed; the gangue minerals contained in DRI combine with the added lime to form a fluid slag.

Zinc is initially oxidized to form a zinc oxide dross on the surface of the charge, but as lead oxide subsequently forms, a fluid slag of zinc and lead oxides is created.

Then, full driven still, but now operating at maximum aperture he drove it in a dizzying spiral outwardly from the dome, fusing the entire unprotected area of the metropolis into a glassily fluid slag of seething, smoking desolation.

Precolonial iron workers in present South Africa even smelted iron-titanium ores that cannot be used by modern blast furnaces.This is because titanium oxide is not reduced in bloomeries, and mixes readily with iron and silica to produce fluid slags.