THE FORMING OF MAGNESIA SLAGS WITH RATIONAL COMPOSITION IN COURSE OF HIGH-PHOSPHORUS CAST IRON CONVERSION AND THE HARD-WEARING SLAG SKULL APPLICATION ON THE LINING WITH THE USING OF MAGNESIA-ALUMINA FLUX

Abstract

The conversions of high-phosphorus cast  iron  in course of steelmaking in 300-t  oxygen  converters under the  magne- sia slags of the  rational composition at the  «ArselorMittal Temirtau» Stock  Company are  regarded in the  article. The special technology is developed and  considered which  in- cludes both  the  forming of  the  saturated  magnesia slag (8–11 % MgO) with the  basicity 3,0–3,4 till the  end  of the oxygen  lancing process and  the  installation of hard-wearing skull  coating (with  the  durability 1–2 meltings) on the lining  in course of slag’s  blowing with high-pressure nitrogen  and  with  magnesia-alumina flux (MAF) additions. The application of MAF provides the MgO’s high concentration in the slag (up till 9–10 %) with the keeping of needed limit of phosphorus removal (97,1–98,1 %) given  that the  average  phosphorus content in  the  metal is  0,013–0,017  %. Ill. 3. Tab. 1.