Abstract: A particulate flux composition suitable for desulphurizing and/or dephosphorizing molten ferrous metals and for use as a mould flux comprises prefused particles comprising calcium oxide and at least one other component, such as alumina, iron oxide, calcium fluoride, magnesium fluoride, sodium fluoride, silica, sodium oxide, zirconium oxide, titanium oxide or sodium borate, and in which each particle has a substantially vitreous amorphous structure. The composition is highly resistant to hydration and does not introduce hydrogen into the molten metal.

Abstract: Treatment agents for steel suitable for desulphurizing molten steel comprise granules containing both magnesium oxide and/or carbonate and aluminium, the proportion of aluminium in the surface of the granules being substantially less than the overall proportion of aluminium in the granules. The granules are suitable for application into the molten steel via injection techniques.

Abstract: Method of desulphurizing a ferrous melt comprises injecting into the melt lime-containing particles having smooth surfaces, a low tendency to absorb moisture and blocked pores formed by solidification of molten inorganic matter in the pores of the lime. Method of making a desulphurization agent for the desulphurizing method comprises calcining limestone with, for example, sodium carbonate, calcium fluoride or siliceous matter. Desulphurization agents per se are also described.