OXYGEN STEEL-MAKING CONVERTER METHOD Russian patent published in 1995 - IPC

FIELD: metallurgy. SUBSTANCE: molten metal and slag formed as a result of production of synthetic slag are introduced into converter as heat-transfer agents. Oxygen lancing is performed in two phases, with slag flushing in between. Scrap and lime are introduced in portions depending on the oxygen lancing period. In the first oxygen lancing period a 80-90 % of all scrap used in the melting is introduced. Lime is introduced by portions: the first portion - 28-29 % of the whole amount introduced onto the bottom of converter, the second portion (28-29 %) after 12-15 % of the total time of oxygen lancing, and the third portion (28-29 %) after 40-45 % of the lancing time. During the second period of lancing, 10-20 % of scrap is introduced and 13-16 % of the whole amount of lime is added after 70-75 % of the whole time of oxygen lancing. The total amount of scrap is in a 3 to 1 relation to the molten metal. In the first period of lancing the amount of lime introduce is cut down to a 2 to 1 proportion of the mass of accompanying slag. The silica slag is removed after 65-70 % time lapse from the start of the whole of lancing process. To reduce the amount of slag and metal flushed from the converter, the initial period of lancing should be 12-15 % of the total time of lancing. EFFECT: higher efficiency. 2 cl, 2 tbl