Until this summer, molten iron was desulphurised at Lackenby by injection of a calcium carbide reagent into the 320-tonne capacity torpedo ladles in which it arrived from a nearby site. This process took place outdoors. The iron was then poured into an open-topped ladle and the sulphur-containing slag skimmed off the surface.
The injection process generated large quantities of iron oxide fume. Some of this was discharged through a stack w