Abstract: The parameters of converter oxygen lance nozzle and the bottom blowing flow rate were optimized in No.3 Steelmaking Plant of WISCO. The splashing frequency decreased from 3.4% to 1.5% in blowing process, the slag T.Fe mass fraction reduced from 15.99% to 15.49% at the end point of blowing, good blowing effect was achieved. At the condition of monitoring the bottom thickness by laser measuring thickness, extending visible porous brick life up to 4 000, improving the bottom blowing gas flow to 1 100m3/h, using 8~16 visible porous bricks, [%C]•[%O] was in 0.001 5~0.001 8 at blowing end, which achieved better metallurgical effects. The parameters of oxygen lance nozzle and the lance profile in blowing process were optimized in No.4 Steelmaking Plant, the problem of scrap melting was solved. The stirring mode was optimized through the large gas flow stirring test at the end blowing. When using 4 visible porous bricks and stirring flow 500m3/h, stirring time for 3~4 minutes, the mass fraction of oxygen reduced 20.47×10-6 average per minute in molten steel, the mass fraction of carbon reduced 29.23×10-6 average per minute.

Key words: oxygen lance nozzle, bottom blowing, porous brick, carbon-oxygen equilibrium