Abstract: The method concerns the desulphurization of cast iron produced by a blast furnace, before it is converted to steel.In a first phase of the process the cast iron is treated with a desulphurizing compound such as Na.sub.2 CO.sub.3. A very long composite product with a tubular skin is then added to the cast iron. The product comprises an axial zone containing magnesium in powdered or granular form, and an annular zone, separated from the axial zone by an intermediate wall and containing a powdered or granular material. An inert gas could then be injected and a clearing operation carried out.

Abstract: The disclosed method is a method of manufacturing clean steel comprising refining molten steel by adding additives of from not more than 0.5% to more than 0.001% by weight of molten steel to the molten steel bath, in vacuo or a non-oxidizing atmosphere within a melting furnace or vessel made of or lined with a basic refractory material consisting essentially of 7-90 wt % of CaO and 90-7 wt % of MgO, which total content being 70% to 99.9%, and optionally included a basic refractory material consisting of 30-0.1 wt % of at least one element selected from the group consisting of Al.sub.2 O.sub.3, CrO, ZrO.sub.2.SiO.sub.2, ZrO.sub.2, ZrC and C as selected components, and obtaining clean steel containing less than 30 ppm of oxygen, less than 30 ppm of sulfur, less than 150 ppm of nitrogen, 5 to 0.1 ppm of Mg and 25 to 0.1 ppm of Ca. Said additives comprises Al and at least one optional element selected from Ti, Nb, Ta, B and alkali earth metal. 5% of a solvent can be included to said additives.